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.

40세 이하 관상동맥 질환자에서 장기적 임상 관찰

이승욱,정명호,박종철,박형욱,조상희,김원,김계훈,이상현,강경태,조장현,김남호,김건형,안영근,조정관,박종춘,강정채 全南大醫大 2001 전남의대학술지 Vol.37 No.2

플라즈마 표지소자의 제작

이상윤,라병욱,박동수,황인헌,이덕동,신영남,박성배,이동욱,박용석,박형근,손상호,권태근,채경락,정경득 慶北大學校 自然科學大學 1986 自然科學論文集 Vol.4 No.-

An Ac-type Plasma Display Panel (PDP) operating with Ne-Ar(0.1%) Penning mixture gas is fabicated. The characterics of the panel with electrodes covered with thin and thick dielectric layers are studied. The brightness of the Neon-orange light emitted by the panel measured as function of applied voltage and frequency. As an application, a graphic display system equipped with PDP showing still and moving pictures is made.

스테이지 이동 반력에 의한 베이스 진동 저감기법 개발

박아영,김형기,권오영,홍성욱 한국공작기계학회 2009 한국공작기계학회 춘계학술대회논문집 Vol.2009 No.-

A variety of precise stages are adopted for precise machinery. To secure vibration isolation, those precise stages are mounted on a heavy base structure supported by compliant springs. Then the base structure is often subjected to vibration due to the reaction force induced by the stage motion. This paper investigates the dynamic behavior of base structures as well as a vibration reduction technique. A 6 DOF dynamic model is established to investigate the vibration of positioning stage and base structure. A new input shaper is devised to eliminate both the residual vibrations in base structure. Simulations show that the proposed input shaper effectively remove the residual vibrations in base structure.

악관절 자기공명 T2 강조영상에서 Joint effusion에 관한 임상적, 방사선학적 연구

박광호,김경욱,김형곤 대한 두개하악장애학회 1994 대한두개하악장애학회지 Vol.6 No.2

Two of the methods for the examination of inflammatory changes in the synovial fluid of TMJ are ; aspiration and magnatic resonance imaging. While the aspiration method is invasive and limited by technical difficulties, magnatic resonance imaging, which could be classified as T1 or T2-weighted images, could visualize changes in volume and content of synovial fluid by inflammation through T2-weighted images only. Such inflammatory changes are among the factors causing pain in TMJ, and imaged as joint effusion, which is a high signal intensity within the joint cavities, and edema of posterior attachment. This detection of internal changes may be important in the choice of the method and prognosis of the treatment for TMJ. This study compared and analyzed T1 and T2-weighted images and examined T2-weighted images of joint effusion and edema from those patients who were tenatively diagnosed with internal derangement. The results were as follows : 1. Among the total of 128 patients and 131 joints, 13% were normal, 38.2% were anterior displacement with reduction, 42.7% were anterior displacement without reduction, and 6.1% were perforations. When morphological changes of meniscus were present, they appeared in 26 joints with the anteior displacement with reduction, and in most of the anterior displacement without reduction. Degenerative changes of the condyle heads were observed in 20 joints with anterior displacement without reduction, and in all 8 cases with perforation. 2. Joint effusion and edema images on MR T2-weighted images were present in 59 out of 131 joints(45.1%). 3. Presents of joint effusion was rare in normal and slight disc displacement cases, most frequent in the advanced disc displacement cases, and as it progressed toward perforation, tend to be rare again. That seems to indicated that joint effusion is associated with disc displacement. 4. Association between joint effusion and pain was highly significant; displacement with reduction showed 81.8%, without reduction 88.6% with total of 86.4%. 5. In the diagnosis of TMJ through magnetic resonance imaging, T2-weighted images can detect pathological changes and therefore seem to be more effective than the routine T1-weighted images.

2000-2008년 수도권 지역의 가와사끼병의 역학적 연구

박형준,김영대,김우경,송영환,김동욱,박용원 인제대학교 2009 仁濟醫學 Vol.30 No.-

Objectives : The aim of this study was to investigate the clinical features and epidemiologic pattern of Kawasaki disease(KD) in Seoul metropolitan area for the 9-year-period. Methods : An epidemiologic survey on KD was retrospectively performed. The questionnaire was sent to 3 hospitals including Seoul Paik hospital, Sanggye Paik hospital and Ilsan Paik hospital, and obtained data were analyzed. Results : Data from a total of 1,297 cases were collected. The male-to-female ratio was 1.33:1(741:556), and the mean age of onset was 32.2 months. The monthly number of patients was slightly higher in May, June and December. There was no sibling case and rate of recurrence cases was 2.31%(30/1,297), and the proportion of patients with KD among total hospitalized pediatric patients was 2.05%. Coronary arterialu..A) abnormalities were detected at follow-up by echocardiogram in 17.2%(204/1,185) of cases including 0.76% of aneurysms. Conclusion : Comparing with the data of the KD patients in Korea(1.48%), our data of 1,297 KD patients area showed higher proportion of patients with KD among total hospitalized pediatric patient(2.05%).

작업장 특성에 따른 톨루엔 노출 근로자의 마뇨산 배출 특성

박흥재,김형준,정성욱,이병호 한국환경과학회 2005 한국환경과학회지 Vol.14 No.2

This study was carried out to investigate the correlation between toluene in air and hippuric acid in human urine, which is based in the results of the health check-in and measure of working environment, was investigated for five years. Toluene in air and hippuric acid in urine were checked 116 workers who exposed to toluene in five type of industry. The Mean concentration of toluene in air by type of industry and every year and sex distinction, had positive correlation.(p<0.01) The Mean concentration of hippuric acid in urine by type of industry, every year, sex distinction, disparity of age and term of duty had positive correlation.(p<0.01)

Benoist씨 장치를 이용한 소아의 하악 과두 골절의 치험례 : A CASE REPORT

박상욱,최형준,차인호,김성오,최병재 大韓小兒齒科學會 2004 大韓小兒齒科學會誌 Vol.31 No.3

소아에서의 하악 골절은 성인에서보다 드물다. 그러나, 어릴수록 강직과 성장장애의 가능성이 크며 성인만큼 악간고정을 잘 견뎌내지 못한다. 반면에, 골절은 소아에 있어 더 빨리 치유되고 합병증도 적다. 소아에서 하악 골절은 종종 하악의 acrylic splint therapy 단독 또는 eyelet wire 와 악간 고정을 같이 사용하여 성공적으로 치료될 수 있다. 발생할 수 있는 심각한 합병증으로는 유착과 성장장애가 있다. 이러한 합병증의 빈도와 심 각성은 좀더 짧은 기간의 악간고정과 긴밀한 술 후 관리에 의해 감소될 수 있다. 특히 소아 환자가 악간고정을 잘 견디지 못하는 경우, 악간고정의 기간이 길어지는 경우, 환자의 자발적인 운동요법이 어려운 경우, 악간고정이 불필요하고 개구장애 만을 일으킨 미약한 증상의 경우에는 동기부여에 의한 물리적 하악 운동요법이 사용될 수 있다. 본 증례에서는 하악 정중부의 외상으로 인하여 양측성 과두 골절이 일어난6세 여자 환아를 대상으로 상,하악에 elastic을 이용하여 하악의 개구, 측방 전방운동에 대해 훈련을 가능하게 하는 Benoist씨 장치를 이용한 능동적 하악 운동 요법으로 7개월 간의 정기 검진을 통하여 하악 운동량의 증진, 과두 유착의 방지, 골개조의 치료효과를 보였다. Mandibular fracture is less common in children than in adults. However children are more susceptible to ankylosis and developmental disorders, and don't respond as well to intermaxillary fixation compared to adults. On the other hand, bone fracture is healed more quickly in children and complications are scarce. Mandibular fracture in children is usually treated successfully with acrylic splint therapy with or without the use of eyelet wires and intermaxillary fixation. Severe complications that include ankylosis and developmental disorders may occur. The frequency and severity of such complications can be mitigated with a shorter duration of intermaxillary fixation and good post-operative care. Encouraging mandibular physical therapy by increasing patient motivation may be necessary in such cases where the patient's response is poor and the duration of intermaxillary fixation increases; when the patient is unable to undergo physical therapy, or when intermaxillary fixation is not necessary with the patient showing only minor symptoms such as trismus. In this case report, a 6 year-old girl with bilateral condylar fracture was treated with elastic in both the upper and lower jaws to allow mandibular physical therapy using a Benoist's appliance, which allows opening, lateral, and protrusive retrusive movements of the mandible. A 7-month follow-up showed beneficial therapeutic effects such as increased mandibular movement and prevention of condylar ankylosis.

셀레콕시브 및 그 합성유도체들의 항암활성 스크리닝

박정란,강진형,구효정,노지영,류형철,박상욱,고동현,조일환,이주영,황다니엘,김인경 한국약제학회 2003 Journal of Pharmaceutical Investigation Vol.33 No.2

Selective COX (cyclooxygenase)-2 inhibitors including celecoxib have been shown to induce apoptosis and cell cycle changes in various tumor cells. New inhibitors are recently being developed as chemomodulating agents. We evaluated celecoxib and screened 150 synthetic compounds for anti-proliferative activities in vitro. Effects of celecoxib on COX activity, cell growth, cell cycle distribution, and apoptosis induction were determined in A549 COX-2 overexpressing human non-small cell lung cancer (NSCLC) cells. The COX inhibition of celecoxib increased with concentration up to 82% at 1μM after 24 hr exposure. Forty μM and 50μM of celecoxib induce G_1 arrest, and TUNEL-positive apoptotic cells, respectively. Among 150 compounds, several compounds were selected for having greater COX-2 inhibitory activity and higher selectivity than celecoxib with growth inhibitory activity. Celecoxib showed concentration-dependent COX inhibitory activity, and ability to induce cell cycle arrest and apoptosis in human NSCLC cells in vitro. Among synthetic analogues screened, several compounds showed promising in vitro activity as COX-2 inhibitory anticancer agents, which warrant further evaluation in vitro and in vivo.

국내 제조기업의 경영전략에서 생산기술 역할에 관한 실증적 연구

金炯郁,朴眞洙,鄭元勳 홍익대학교 경영연구소 1996 경영연구 Vol.21 No.-