Insulation Coating of Fe–Si–Cr Soft Magnetic Powder by Selective Oxidation

Jae‑Young Park,Kwangsuk Park,Bosung Seo,Julien O. Fadonougbo,Tae‑Wook Na,Ki Beom Park,Hyeon‑Tae Im,Nong‑Moon Hwang,Hyung‑Ki Park 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.7

This study examines the insulation coating technology of Fe–Si–Cr powder via selective oxidation annealing, which oxidizeselements selectively by controlling the oxidation potential. The study calculated the oxidation driving force of Fe, Si, andCr, and conducted a thermodynamic analysis of oxidation and reduction conditions according to temperature and oxidationpotential. Based on the results, a selective oxidation annealing was performed in an atmosphere in which Fe is reduced andonly Si and Cr are selectively oxidized. The oxidation potential was controlled through the partial pressure ratio of hydrogenand water vapor. The XPS analysis results confirmed that a Si and Cr complex oxide layer formed on the powder surfaceafter the selective oxidation annealing. Afterward, withstanding voltages were analyzed to evaluate the insulation property. Then, the withstanding voltage of the powder applying the selective oxidation annealing increased significantly comparedto that of the initial powder. Further analysis showed that the powder annealed in an air atmosphere had a significantly lowersaturation magnetic flux density than the initial powder, while the powder applying the selective oxidation annealing hadonly a slightly reduced saturation magnetic flux density.

북한산국립공원의 계류수질 보전 전략(I)

박재현,우보명,김우룡,안현철,조현서,추갑철,김춘식,최형태,Park, Jae-Hyeon,Woo, Bo-Myeong,Kim, Oue-Ryong,Ahn, Hyun-Chul,Cho, Hyun-Seo,Choo, Gab-Chul,Kim, Choon-Sig,Choi, Hyung-Tae 한국환경복원기술학회 2001 한국환경복원기술학회지 Vol.4 No.3

This study was conducted to investigate physicochemical property changes from July 1998 to August 2001 in Mt. Bukhansan National Park. Four water sampling points were selected to measure the quality of stream water in the northeastern part of the Mt. Bukhansan National Park. The results were summarized as follows; In spring, the average pH of stream water was below the first class of the river water quality standard, while it was normal level in summer. The average electrical conductivity was about 2.3~3.3 times higher in downstream water than in upstream water during spring and summer. The contents of anions($Cl^-$, $NO{_3}^-$, $SO{_4}^{2-}$) were about 1.1~7.4 and 0.4~11.4 times higher in downstream than in upstream water, respectively. These results indicate that water quality was poorer in downstream than in upstream water. We suggest that stream water in the Mt. Bukhansan National Park should be protected from impacts of snow melting mineral particles in spring season and human impacts like wastewater of point source in summer season.

경주지역 여고생의 초경과 체성장간의 관계

김준섭,권오구,박진석,오종수,박정현,박제식,안세한,이용환,서정호,신태섭,최영배,김덕수,이관,박수경 東國大學校醫學硏究所 2002 東國醫學 Vol.9 No.1

본 연구는 경주지역 1개 고등학교 3학년 여고생을 대상으로 초경 시작 전인 초등학교 4학년부터 고등학교 2학년까지의 키, 몸무게, 가슴둘레 수치와 초경 연령을 파악하여 여성의 초경이 빠를수록 체성장 속도의 변화가 있을 것이라는 가설을 기초로 두 요인간의 관련성을 파악하고자 시행되었다. 경주시 1개 여자고등학교 3학년생 총 317명에 대해 ㅊ경 나이, 초경시 심리 상태, 초경이 시작되었을 때의 상담 여부와 상담하였던 사람, 부모 신장과 초경전후의 식사 규칙성, 다이어트 경험, 수면시간, 스트레스, 음주/흡연 여부, 질병력 등에 대한 설문 조사를 시행하였고, 초등학교 4학년부터 고등학교 2학년까지의 키, 몸무게, 가슴둘레에 대한 정보는 건강기록부에서 확보하였다. 상기 대상자 중 건강기록부가 분실된 39명, 초경나이에 대해 응답하지 않았던 29명 및 결석 등으로 조사를 하지 못하였던 42명을 제외한 조사 대상자는 206명으로 선정하였다. 대상자들의 초경연령 평균값(Mean±SD)은 13.0±1.11이었고, 초등학교 4학년부터 고등학교 2학년까지의 초경 이후 신장 성장률은 감소하였으며, 초경연령이 빠른 군이 초등학교 때는 신장에 있어서 우위를 차지하나 고등학교에 오면서 신장은 비슷한 수준이 되었다. 초경후 1-2년 사이에 체중과 흉위의 증가율은 감소하였고, 초경연령이 빠른 군이 초등학교와 고등학교 사이에 체중과 흉위에서 모두 우위를 차지하였다. 본 연구의 결과는, 흔히 이차 성징의 시작 시점 혹은 사춘기의 시작 시점으로 보고있는 초경 연령이 청소년기의 성장과 밀접한 관련성이 있고, 특히 체중과 흉위의 성장 속도와 밀접한 관련성이 있음을 시사한다. To understand the onset of menarche in relation to changes in physical growth that take place during female adolescence, especially the changes in height and weight velocity. The 207 senior in one women high school of Kyongju were investigated in April 3 to 8, 2001. We collected the information, relation in the age at menarche, height & weight of parents, regularity of eating, and obesity diet, duration of sleeping, sickness & stress near age at menarche, by self-recording. The status of height, weight & chest circumference between the 4th grade of primary school and the junior of high school was collected by individual Health Record. The results were followed; The average age at menarche was 12.95±1.11 years old and the most frequent age of menarche is 13 years. After menarche, the velocity of height, weight and chest circumference were decreased. The most rapid group of menarche hold dominant position in height during elementary school. As time passed, they dont hold dominant position in height. The most rapid group of menarche get an advantage in the weight and the girth of chest after elementary school. The height of subjects is directly proportional to the height of their parents. These results suggest that the starting age at menestuation can be closely associated with physical growth and development.

공동주택 장기수선계획 시스템 개발을 위한 분석ㆍ설계단계에 관한 기초적 연구

서민구,정영한,박태근 대한건축학회 2004 대한건축학회 학술발표대회 논문집 - 계획계/구조계 Vol.24 No.1

Extension of building life cycle and reduction of maintenance and management relevant expenses are the top issues in the current construction market. The fields of maintenance and management are newly highlighted for the limited land and domestic economic crisis known as the 2nd IMF. We studied on the long-term maintenance plan of apartment buildings in order to analyze the defective management system of existing apartment building and secure the development-oriented management system in this study. Purposes of this study are to prevent the unwanted loss of manpower and capital resulted from the careless storage of repair and management records, extend the building life cycle and resolve the conflict caused by the uncomfortable relation with the occupants. This study is focused on presenting the potential to develop the process required for the basic analysis and development of system as the beginning stage in the process of developing the long-term maintenance plan.

퍼팅 동작 영상분석 시 프레스 동작의 이벤트 설정 가능성 여부

박태진,서국웅,서국은 釜山大學校 附設 體育科學硏究所 2009 體育科學硏究所 論文集 Vol.25 No.1

본 연구는 부산.경남지역에서 세미프로로 활동 중인 7명을 선정하여 퍼팅(10.94 m)동작 시 프레스 동작을 3차원 영상 기법을 통해 운동학적으로 비교.분석하여 얻은 결론은 다음과 같다. 첫 번째, 양손은 어드레스를 취한 후 백스윙되기 전까지 볼 진행 방향으로 움직이는 것으로 나타났다. 두 번째, 퍼터헤드, 몸통, 어깨 중심점은 프레스 동작 시 좌.우 방향으로 움직이지 않고 고정되어 있는 것으로 나타났으며, 프레스 시 양손 중심점은 어드레스 시 보다 임팩트 시에 가까운 것으로 나타났다. 세 번째, 퍼팅 스트로크 시 총소요시간 중 프레스 동작이 22.83%를 차지하고, 구간 중 다운스윙과 팔로스루 시간 보다 많이 소요되는 것으로 나타났다.

상악궁 확장술을 통한 치료전,후 및 보정후 상악 구치부 변화에 관한 연구

박태서,이진우,차경석 대한치과교정학회 1997 대한치과교정학회지 Vol.27 No.1

치열궁의 크기와 폭경 변화에 대한 연구가 사용된 장치형태, 사용시기에 따라, 그리고 사용 목적에 따라 다양한 연구가 활발히 이루어져 왔다. 또한 Quad-helix도 선학들에게 관심의 대상이었으며 Quad-helix의 안정성과 장치 사용 전, 후에 대한 효과도 연구가 이루어졌다. 그러나 장치 사용에 대한 장기적인 효과에 대한 연구가 미흡하여 본 논문은 이 장치를 사용하여 치료한 환자의 치료 전, 후 및 보정후의 치열궁 변화에 대한 연구를 시행하여 Quad-helix사용 전, 후 구치부의 적응 양상을 연구함으로써 임상에서 Quad-helix를 통한 치료를 시행할 때 이 장치사용에 따른 효과 및 예후에 대하여 효과를 이해함으로써 교정치료에 도움을 주고자 연구를 시행하여 다음과 같은 결과를 얻었다. 1. Quadhelix를 사용한 교정치료시 상악 제 1 소구치와 제 1 대구치는 치료전과 치료 후 및 보정후에서 교두간 폭경의 증가를 보였고 제 2 소구치에서는 치료후와 보정후간에 유의성있는 증가를 보였다. 2. 상악 제 1 소구치와 제 1 대구치의 치축은 치료전과 치료후 그리고 보정후에서 협측 경사도가 유의하게 증가를 보였으며, 상악 제 2 소구치는 치료전과 치료후 및 치료전과 보정후 비교에서 설측 경사도가 유의하게 증가를 보였다. 3. 최대 풍융부 항목에서 상악 제 1, 2소구치는 치료전과 치료후의 비교에서 유의한 증가를, 제 1 대구치에서는 치료 전, 후, 및 보정후에 유의한 증가를 보였다. 4. 상악 제 1 대구치의 설면구 폭경은 치료전, 후 및 보정기간을 통하여 유의한 증가 를 보였고, 구개 높이는 치료전과 치료후 비교시 유의한 증가를 보였다. 5. 확장시킨 상악 치열궁은 회귀현상을 보이지 않고 안정적으로 유지되었다. The purpose of this study was to measure the changes of arch and dentition of maxillary posterior teeth before and after treatment and postretentios in patients treated with Quad-helix. Measurements and analysis were performed on study model with carlipers. Seventeen cases, eight boys and nine girls, were selected with average ages of 12.7 years. Mean retention period was 4 months, and mean wearing time was 127 days. The result were as follows 1. The interpremolar widths and intermolar width were significantly increased in maxillary first premolar and molar when compared between before and after treatment and postretention. The maxillary second premolar resulted in significant increase in interpremolar between after treatment and post retention. 2.The long axis of maxillary first premolar and first molar accompaning buccaltipping was significant increased before and after Tx and post retention. Significant increase of the lingual inclination of maxillary second premolar was obsered both in before and after Tx, and before Tx and post retention. 3.The distance between the height of tooth contour was significantly increased in the first and second premolar before and after Tx, and was significant increased in the first molar before and after Tx and post retention. 4.Intermolar width at the palatal groove was increased in before and after and after Tx. and post retention. The palatal depth was significant increased in before and after Tx. In conclusion, expansion of maxillary dental arch showed no relapse and results were stable retention.

지구성 운동이 중년여성의 혈중지질농도에 미치는 영향

朴麟基,崔大雨,李明秀,徐在河,趙炳俊,金泰亨 충남대학교 체육과학연구소 2000 體育科學硏究誌 Vol.18 No.1

The purpose of this study was to identify the effect of endurance exercise program on the middle-aged women. Six subjects were recruited from among volunteers responding to advertisements placed around the university community. All subjects, with no experience in regular physical activity participated in an interventional training consisting of swimming and stretching three days a week for 10weeks. Pre-and post blood lipid levels, such as Total Cholesterol(TC), High Density Lipoprotein Cholesterol(HDL-C), Low Density Lipoprotein Cholesterol(LDL-C), and Triglyceride(TG) were measured. A paired t-test showed results that were significant the .05 level were HDL-C , LDL-C, TG, and TC/HDL-C Ratio. The main finding of the study was that the role of endurance training, as prescribed in our study has the effect of making improvements in blood lipid levels for the middle-aged women. 1. After a 10week period of endurance exercise, the Total Cholesterol(TC) level was higher than that of pre-test. But the difference no showed the statistical significance. 2. After a 10week period of endurance exercise, the High Density Lipoprotein Cholesterol(HDL-C) Low Density Lipoprotein Cholesterol(LDL-C). Triglyceride(TG) level was higher than that of pre-test. and the difference showed the Statistical significance. In conclusion, even though there was significant in blood lipid levels after endurance exercise, swimming has a beneficial on improving in the middle-aged women.

아세토니트릴 용매 중에서 Copper-1,5,9,13-Tetrathiacyclohexadecane 착물의 전기화학적 거동과 그 분석적 응용

徐戊龍,李富永,崔明子,裵俊雄,朴泰明 慶尙大學校 기초과학연구소 1992 基礎科學硏究所報 Vol.8 No.-

비수용매인 아세토니트릴 중에서 Cu(Ⅱ)dhk 1,5,9,13-tetrathiacyclohexadecane[16-ane-S_4]의 착물에 대한 전기화학적 거동으로서 직류폴라로그램과 미분펄스폴라로그램으로부터 환원전류의 유형과 가역성을 조사하고, 이들 화합물의 분석적 응용으로서 수용액에 있는 Cu(Ⅱ) 이온을 염석추출법으로 정량하였다. 또한 아세토니트릴 용매 중에서 착물의 안정도상수를 구하고, 분석적 응용으로 수용액 중의 Cu(Ⅱ)를 염석추출법으로 정량하기 위하여 추출 조건 곧 킬레이트와 염석제의 효과, pH 범위를 구하고 또한 Cu(Ⅱ)이온을 정량하는데 있어서의 검량성과 공존이온 효과를 조사하였다. 실험결과로부터 환원 과정은 비가역적이었으며 환원전류는 확산지배적임을 알았다. 또한 아세토닐트릴 용매 중에서 착물의 log K_f 값은 3.51이었으며 Cu(Ⅱ) 이온을 정량하는데 있어서 공존하는 이온의 영향을 별로 받지 않아 선택성이 좋았으며 본 실험방법에 의한 정량한계는 60ppb 이었다. The electrochemical behaviors and analytical application of copper-1,5,9,13-tetrathiacyc-lohexadecane[16-ane-S_4] complex in acetonitrile(AN) solution have been investigated by the use of Dc polarogaphy and differential pulse polarography. Thus the formation constant of copper complex was 10^3.51. Copper (Ⅱ) ion was found to form complex of 1-to-1 composition with [16-ane-S_4]. In addition, reduction step was irreversible and the reduction current was diffusin controlled. And the effect of concentration of the salting-out reagent and chelating agent and pH of aqueous phase on the determination of copper(Ⅱ) was investigated and diverse ion effect was discussed. By salting-out extraction technique, we can be determined until the concentration of cooper (Ⅱ) of 60 ppb.

초등학교 교사들의 과학과 실험연수에 대한 의식 조사

서승조,조태호,백남권,김성규,박강은,정순호 晋州敎育大學校 科學敎育硏究所 2001 科學敎育硏究 Vol.27 No.-

This study investigated the perceptions of elementary school teachers' on the science experimental training course using closed-form questionnare. 437 elementary school teacher, 21 school, 14 cities and counties in Gyung Nam province were selected as the objects for researching these matters. The results were as follows; First, without system and holding type teachers choose on the training not the same time but their ability freely. Second, to extend the trust the composition of place and instructor must be based on professor and research in the national university of education. Third, the composition of the text must be made of scientific growth based on important experimental activities teaching strategy, the using of materials. It must be increase multimedia training course on the science education. Fourth, the method of training course it must be happen on the experiment and discussion and it is necessary to grow up training level. Fifth, the type of training it must not give the score. Therefore it will be free and comfortable without difficulties. In the results, the improvement of science experimental training course is compatible on the purpose and it will help on the science teaching-learning.

전립선암과 전립선비대증 환자에서 혈청 유리 및 총전립선특이항원 측정의 의의

서혁준,박형민,권태균,정성광,김법완,이재태 경북대학교 의학연구소 2000 경북대학교병원의학연구소논문집 Vol.4 No.1

Purpose: This study was peformed to investigate whether the free to total PSA ratio(F/T PSA ratio) offers a better discriminant for the detection of patient with prostatic cancer(CaP) and those with benign prostatic hyperplasia(BPH) than serum total PSA alone. Materials and Methods: From September 1996 to February 1999, free and total PSA levels were measured on frozen sera samples of 154 men with BPH and 46 with CaP using immunoradiometric assay. Results: In all subjects, the mean total PSA was significantly higher in CaP group(72.57±66.58ng/ml) than BPH group(3.12±4.10ng/ml). The mean PSAD was significantly higher in CaP group(1.64± 1.86) than BPH group(0.08±0.01). The mean F/T PSA ratio was significantly lower in CaP group(0.19± 0.07) than BPH group(0.30±0.13). Among 41 subjects whose total PSA were between 4-20ng/ml, the mean PSAD was significantly higher in CaP group(0.37±7.16) than BPH group(0.17± 0.07), but the mean F/T PSA ratio was not significantly different between CaP(0.19± 0.10) and BPH group(0.25±7.13). By comparing the sensitivity and specificity of total PSA alone, PSAD and F/T PSA ratio on receiver operating characterislic (ROC) Cutie in all subiects and subiects with total PSA between 4-20ng/ml, F/T PSA ratio had no superiority than total PSA alone and PSAD for discrimination between CaP and BPH. Conclusions: We suggest that the F/T PSA ratio is not superior to total PSA alone and FSAD in the detection of prostatic cancer, and further evaluation of the usefulness of F/T PSA ratio should be required.