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.

품종별 감꽃 동결건조 분말의 유효성분 분석

김준한 ( Jun Han Kim ),박석희 ( Seok Hee Park ),문혜경 ( Hye Gyeong Mun ),이인선 ( In Seon Lee ),김종국 ( Jong Kuk Kim ) 한국식품저장유통학회 ( 구 한국농산물저장유통학회 ) 2006 한국식품저장유통학회지 Vol.13 No.6

감 품종별(도근조생, 고종시, 갑주백목, 차랑, 월하시, 상주둥시)로 감꽃을 개화기에 채취하여 동결건조 분말화한 감꽃분말에 함유된 유효성분을 분석, 비교하였다. 조지방 함량은 도근조생이 57.26%로 가장 높은 값을 보였으며, 유리당 조성은 fructose가 95~310 mg%, glucose는 75~281 mg%, sucrose가 7~28 mg%의 함유량을 나타내었고, 유기산 중 malic acid가 갑주백목(6월4일)에 225 mg%로 가장 많았고, tartaric acid도 189 mg%로 가장 많았다. 유리아미노산 중 hydroxy-L-proline은 월하시에 25.33 mg%, L-citrulline은 상주둥시(5월28일)가 58.83 mg%, L-threonine은 상주둥시(5월28일)가 11.88 mg%로 가장 많았다. 페놀산으로 caffeic acid는 갑주백목(6윌4일)이 1946 μg/100 g, phydroxybenzoic acid는 상주둥시(5월29일)가 417.8 μg/100 g, protocatechuic acid는 갑주백목(6월1일)이 181.1 μg/l00 g으로 가장 많았다. 따라서 감꽃에도 감이나 감잎에 못지않게 유용한 식품성분들과 기능성 성분들이 다량 함유되어 있어 새로운 식품 및 기능성 신소재로서의 가치가 매우 높다고 할 수 있다. This study was carried out to analyze useful components in freeze-dried persimmon flower powder made from six cultivars. The cultivars were Dogunjosang, Kojongsi, Kabjubaekmok, Chalang, Weolhasi and SangjuDungsi. Powder of persimmon flower was prepared by milling after freeze drying at -70℃. Crude lipid was the highest in Dogunjosang (57.26%). Major free sugars of the persimmon flowers were fructose (95~310 mg%), glucose (75~281 mg%)and sucrose (7~28 mg%). Major organic acids were malic acid (225 mg% in Kabjubaekmok (Jun. 4th)) and tartaric acid (189 mg% in Kabjubaekmok (Jun. 4th)). Predominant free amino acids were hydroxy-L-proline(25.33 mg% in Weolhasi), L-citrulline (58.83 mg% in SangjuDungsi (May 28th)) and L-threonine (11.88 mg% in SangjuDungsi (May 28th)). Major phenolic compounds in the persimmon flowers were caffeic acid (1,946 μg/100g in Kabjubaekmok (Jun. 4th)), p-hydroxybenzoic acid(418 μg/100g in SangjuDungsi (May 29th)) and protocatechuic acid(181 μg/100g in Kabjubaekmok(Jun. 1st)). The results suggest that persimmon flowers be potential materials as useful food ingredients.

Clinical usefulness of infrared thermal imaging as a non-invasive screening test for diagnosis of vascular malformations

( Chihyeon Sohng ),( Jun Hong Park ),( Won Kee Lee ),( Jun Young Kim ),( Yong Hyun Jang ),( Weon Ju Lee ),( Seok-jong Lee ) 대한피부과학회 2018 대한피부과학회 학술발표대회집 Vol.70 No.2

Background: Infrared thermal imaging (ITI), aka thermography, has been used widely in medicine, but been studied rarely its clinical application in vascular malformations (VMs). Objectives: This study investigated validity and usefulness of ITI as a new screening test to differentiate between capillary malformation (CM) and arteriovenous malformation (AVM). Methods: This study included 50 patients with VMs who conducted ITI between 2011 and 2018. They were divided into two groups; CM and AVM, and those with Parkes-Weber syndrome (PWS) were also included in AVM group. Temperature difference (ΔT) between lesional and contralateral non-lesional area was compared using ITI to calculate the maximum ΔT (ΔTmax). The receiver operating characteristic (ROC) curve was then plotted to determine optimal cutoff value of ΔTmax. Results: Of the total 50 patients, 34 were finally diagnosed with CM, and 16 AVM (12 pure AVM, and 4 PWS). AVM group had significantly higher ΔTmax (2.57±1.23°C) than CM group (0.69±0.50°C).The area under the curve of ΔTmax for diagnosis of AVM versus CM was 0.938. The sensitivity and specificity were showed 87.5% and 94.1% (LR+, 14.87; LR-, 0.13) in cutoff value of ΔTmax 1.39°C, and 81.3% and 97.1% (LR+, 27.62; LR-, 0.19) in cutoff value of ΔTmax 1.42°C. Conclusion: The value of ΔTmax measured by ITI was useful to distinguish AVM from CM, so ITI can be employed as a new non-invasive differential screening test for uncertain VMs.

한국에서 온라인서비스제공자의 법적 책임론이 나아갈 방향

박준석 慶熙大學校 경희법학연구소 2008 경희법학 Vol.43 No.3

The legal theory or regulation on the secondary liability of Online Service Provider is roughly divided into two parts, liability requirement and liability limitation requirement. For the OSPs’ liability requirement portion, Korean court seems to have taken unified position in both users’ copyright infringement case and defamation case, pointing out that Joint Tort-feasors rule in Article 760, Clause 3 of the Korean Civil Act is the statutory ground for OSPs liability requirement. For the liability limitation portion, meanwhile, there has been inconsistency of liability limitation requirement in Korean Copyright Act and The Act on Promotion of Information and Communications Network Utilization and Data Protection, thereby making OSPs in Korea suffer from unnecessary legal uncertainty. OSPs’ secondary liability rules in Korea should not follow the US model in which it has been traditionally divided between copyright infringement and defamation. Korea has not differentiated copyright infringement case from other infringement cases including defamation in the secondary liability requirement portion, whereas US has done. Moreover, it can’t be missed that there is a plausible argument for the unification of OSPs’ liability limitation rules even in US. Therefore, OSPs’ secondary liability rules in Korea should be unified over all infringement areas by users, regardless of copyright infringement, defamation, etc., to settle the legal uncertainty in Korea, mentioned above. While the best way would be a new unified law on OSPs’ secondary liability limitation, if it would be severely hard, the second best way to do so is to make immediate amendments harmonizing OSPs’ liability limitation clauses in both acts, Korean Copyright Act, Article 102 & 103 and the Act on Promotion of Information and Communications Network Utilization and Data Protection, Article 44-2. It’s a wrong conception at least in OSPs’ secondary liability area, the way of thinking that defamation cases related to the freedom of speech should be treated differently from copyright infringement cases at all times. In addition, the following differences just can be merely secondary considerations, but never make it very hard to unify OSPs’ secondary liability rules; i) online defamation is usually done through Bulletin Board System rather than Peer to Peer network which has been one of main devices for online copyright infringement, ii) it’s harder in online defamation case to judge the legality of the information at issue and control illegal information than in online copyright infringement case, iii) there is a relatively stronger need to identify direct infringers in online defamation than in online copyright infringement because the former case has relatively fewer infringers than the latter and only the former case has irreparable harm which can’t be compensated by monetary remedies.

호텔 시큐리티에 대한 대응방안

박준석 龍仁大學校 2005 용인대학교 논문집 Vol.23 No.-

It is important assignment to introduce a much better developed country's security system for about a present private security service industry's hotel security(security, guard)manual. It is important to develop a service for a satisfaction of customer totally to the hotel security quality improvement. It is considered a necessity need to be improved qualitatively which can correspond hotel security management and security system about threatening of terrorism according to an era of internationalization's international conference, each kind of events, large scale events.

Numerical Analysis on Crack Generation Behavior of Hypo Peritectic Steel in Continuous Casting Process

Jun‑hyun Jo,Min‑seok Park,Kyung‑woo Yi 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.11

Hypo peritectic steels exhibit a high possibility of longitudinal crack during continuous casting. Therefore, many researchershave studied the mechanisms of crack generation in hypo peritectic steel. Stress in solidified shell, or volume contractionwith small liquid fractions were suggested as the mechanisms of crack generation. A new model was developed for predictingpossibility of crack generation by calculating strain rates in solid, volume contraction rate during solidification, and theprobability of liquid unfilling in continuous cooling processes. The results show that massive transformation from the δphase to the γ phase, and peritectic transformation during solidification can be the main crack generation mechanisms. Furthermore,a linear relationship exists between the amount of undercooling for peritectic transformation (dTp) and the carboncontent of the boundary for dividing the two crack generation mechanisms. Additionally, the longitudinal crack ratios ofthe field results are analyzed through strain rates in solid and liquid unfilling possibilities. Relative positions in the range ofhypo peritectic steel and effective carbon contents are suggested to analyze the crack ratio of steels with alloying elements. This analysis shows that the results obtained from the new models for crack generation possibility are usable, and dTpcangenerate the behavioral differences in crack generation according to the conditions.

벼 乾沓直播栽培時 播種期가 乾物生産에 미치는 影響

朴栽成,朴成圭,李尙榮,洪性澤,池在浚,趙東三,孫錫龍 충북대학교 농업과학기술연구소 1999 農業科學硏究 Vol.16 No.-

This experiment was carried out to obtain indispensable information to establish comprehensive cultural method of rice in direct seeding on dry paddy at Chungbuk Agricultural Research and Extension Services. Effect of seeding date on dry matter production, yield components and yield were studied. Seeding on May 5 ensured the highest maximum number of tillers, while transplanting on May 20 gave the highest rate of effective tillers. Number of effective tillers was greater in the order of Hwajinbyeo, Hwaseongbyeo, Daekwanbyeo. Lengths of upper three leaves were increased at later seeding, but leaf width was not affected by seeding date. Ratio of leaf blade weight was higher in earlier seeding during 30 days before heading but was higher in later seeding during 30 days after seeding, and was higher in the order of Hwajinbyeo, Hwaseongbyeo, Daekwanbyeo. CGR, RGR and NAR were not significantly different among seeding dates during 30 days before heading, but were lower in later seeding during 30 days after seeding. LAR was not affected by seeding date during 30 days before heading, but was higher at seeding on May 5 in heading date and during 30 days after heading. Dry weight of leaf blade, leaf sheath and culm, ear and total biomass during 30 days before heading and heading were highest in May 5 seeding. Daekwanbyeo and Hwaseongbyeo in May 5 seeding and Hwajinbyeo in April 20 seeding brought the highest yield with greater number of spikelets, higher ripening ratio and greater 1,000 grain weight, and harvest index and grain/straw ratio were Increased at earlier seeding. There were significantly positive correlations between number of panicles per m2 and LAI at 30 days before heading and heading, dry matter weight of leaf blade and total mass at heading. On the other hand, there were significantly negative correlations between seeding date and ripened grain ratio. 1,000 grain weight and yield, and between 1,000 grain weight and leaf length of 2nd, respectively.

스포츠 매니지먼트활동에서 매니저들의 책임 수행에 관한 연구

박준석,김정묵,정석현,조영웅,이영성 한국스포츠리서치 2004 한국 스포츠 리서치 Vol.15 No.1

Sport has taken a position as significant influence all over the world for a long time. These days, sport must exist with us in order to provide pleasure, so people have a tendency to expect it what happens to them. Therefore, a number of sport teams and competitions are able to stimulate people to be interested in sport. Sport event, information, equipment, and sport player management need systems which accompany with security and pleasure because the systematical managements establish security, and help sport players not to make an error that is a fountain of good quality game. Thus, sport players improve their ability, so the audience are willing to pay to see the game. In order to extend the power of sport influence, sport should be organized in terms of managing sport processes well. Unfortunately, the system of management for sport is not still adequate and organized in Korea. In other words, many materials must be sporadic, and newspapers or magazines have treated of sport management with fragmentary knowledge so far. Today, systematical management is essential to all segments of the sport industry, professional or amateur, school or club, private or government at any level community or individual. Hopefully, this research will be instructive as a starting point to derive a special quality of sport management which is suited to korea sport market by comparing to other management systems in order to formulate organized management industry.

알코올 사용과 스트레스와의 관련성

전진용,오동열,구민성,이준석,천근아,박웅섭,김상아 大韓神經精神醫學會 2006 신경정신의학 Vol.45 No.4

Objectives : This study was designed to assess the relationship between alcohol use and stress. Methods : The study subjects were 1,261 people who drink among the 2,565 people who lived in Gangneung. We investigated the sociodemographic characteristics, Short Form-12 (SF-12), Global Assessment of Recent Stress (GARS) and Alcohol Use Disorder Identification Test (AUDIT). Results : In Problem drinking group the GARS was significantly positively associated with the AUDIT (p=0.02). In Social drinking group sex (p<0.001) and age (p=0.02) is significantly associated with the AUDIT. Conclusion : This study showed the significantly positively association between stress and alcohol use. We think that the intervention and active management of the stress can prevent the alcohol problem.

국내기업의 테러위협국가 위협의 예방과 과제

박준석 용인대학교 인문사회과학연구소 2009 인문사회논총 Vol.- No.16

As a plan for protection and prevention of domestic enterprises, mutual intimate cooperation in the need to change perception of CEOs, the institutionalization of the companies' counter-terrorism measures system, the cooperation in international agreement or mutual assistance, the help of academic world and private security industries, the necessity for enactment of counter-terrorism laws, the status and directions against the terrorism and stationing and education of experts, and protection of exchanging cultures, sports, and education and visits should be formed. As an option for protecting domestic enterprises getting into state sponsors of terrorism against threat of terrorism, there is the necessity that National Intelligence Service (Integrated Center against Terrorism) organizes integrated management system with administrative organs which are related to itself such as KOTRA, KCCI, KITA, KOICA, embassies, consulate offices, the police, and the military. Moreover, as a protection, it is necessary to make experts at the terrors and security be on duty all times focusing on the state sponsors of terrorism such as Africa and the Middle East to not only prevent also restore and cope with terrorism. Following above, formating network of information of domestic companies entering into states sponsors of terrorism, and studying of cultural, religious, and linguistic parts have to be controlled under the national crisis management. Additionally, the long-termed mutual cooperation between domestic enterprises should be researched. Also, in resources diplomacy of current government, it is considered that the domestic industries' system of protection, prevention, confrontation, and recovery for legal, systematic, administrative, integrated crisis management should be gradually studied.