급냉응고법에 의한 Al-9Zn-2.5Mg-1Cu-X P/M재의 제조 및 성질

임수근 慶尙大學校生産技術硏究所 1990 生産技術硏究所論文集 Vol.6 No.-

Rapidly solidified flakes of 7090 based aluminum alloys containing transition metals were produced by atomizing the alloy melt and subsequent splat quenching onto a water-cooled copper single roll. Consolidation of these flakes was done by cold pressing, degassing and hot extrusion at a reduction ratio of 25 to 1. As splat-quenched flakes showed cellular structure, consisting of primary phase and eutectic. The hardness of flakes and P/M materials increased with the addition of transition metals due to fine dispersion of their eutectic compounds. Mn was most effective for strengthening 7090 based alloy by the addition of transition metals. Tensile strength of T6 materials with 6 wt% Mn addition was 817MPa, and that of 2 wt% Mn addition was 787 Mpa. Furthermore, Mn bearing materials showed appreciably higher specific strength and specific elastic modulus than Ti alloy in room temperature.

혼합치열기의 miniscrew를 이용한 교정치료

임수민,양연미,김재곤,백병주,이용훈,신정근 大韓小兒齒科學會 2008 大韓小兒齒科學會誌 Vol.35 No.2

Anchorage plays an important role in orthodontic treatment, Skeletal anchorage like the miniscrew is considered a more effective method in anchorage control than conventional anchorage which needs much patient s cooperation. The miniscrew offers many advantages. 1) It is easy to insert and to remove. 2) It can endure the force needed for moving teeth. 3) It can be immediately loaded and 4) Patient cooperation is not needed. 5) It is economic compared to other skeletal anchorage systems, In comparison to adult's bones, children s bones have comparatively poor bone quality and quantity. Therefore, it is hard to obtain primary stability in younger patients. However, if the miniscrew can be retained successfully, it will be effective in many orthodontic treatments. In these cases we used the miniscrew in correcting of diastema, in aligning dental midline, and in rendering a forced eruption of impacted tooth in mixed dentition patient. We obtained satisfactory results. 교정치료 시 고정원은 항상 염두에 두면서 치료를 진행해야 하는 중요한 요소이다. 전통적인 고정원을 이용한 치료는 환자의 적극적인 협조를 필요로 하고 원하는 치아이동에 대한 반작용이 나타날 수 있는 등의 부작용을 가지고 있다. 그러므로 보다 견고한 구강 내 고정원이 요구되어져 왔으며 이를 위해 miniscrew가 임상에서 흔히 이용되고 있다. Miniscrew를 통한 고정원의 확보는 구외력 의존도 감소,치료기간의 단축,식립 후 즉시 교정력 적용,환자의 협조도 불필요,식립의 간편성,저렴한 비용 등의 장점을 가지고 있다. 그러나 성장기 환자는 성인에 비해 골질이 좋지 않아 miniscrew의 성공률이 성인에 비해 낮다. 그러나 일단 고정에 성공하면 많은 교정치료 시 매우 유용하게 이용할 수 있다. 본 증례는 흔합치열기 환자를 miniscrew를 이용하여 정중이개 및 정중선 불일치,매복치에 대한 양호한 교정치료를 하였기에 보고하는 바이다.

Mg(OH)₂를 이용한 습식탈황에서 폐슬러리 처리특성연구

김근범,이은덕,박영성,임봉수 大田大學校 環境問題硏究所 1998 환경문제연구소 논문집 Vol.3 No.-

Properties analyses and treatment characteristics of waste slurry discharged in the wetted flue gas desulfurization process using Mg(OH)₂as a absorbent were investigated. Aeration and coagulation test were carried out to evaluate variation of some factors such as COD, SS, T-N, etc. related to waste slurry treatment. The hydraulic retention time(HRT) and coagulant dosage rate were applied as operating variables in experiment. As experimental results, the reduction effects of COD, SS in aeration test were distinct, due to oxidation of SO₃ and floc, formation of suspended solids. It was also found that the reduction efficiencies of SS and T-P in coagulation test are higher than 90%.

AZ91 Mg합금의 시효조직 및 경화거동

강창훈,임수근 국립경상대학교 공과대학 부설 첨단소재연구소 1993 尖端素材 Vol.3 No.-

Microstructure and hardening behaviors were investigated for AZ91 magnesuim alloy solidified in a metal mold. Solid solution treatments were carried out at 683K for various times and final aged from room temperature to 453K. Rockwell hardness, Energy dispersive spectroscopy, optical microscopy and Scanning electron microscopy techniques were used with purpose of indentifying age hardening behaviors with or without heat treatment. While increasing artificial aging temperature shortens the time for initial aging and reaching the peak hardness, too high temperature reduces the amount of age hardening, it is necessary to choose proper temperature suitable to aging time and the amount of aging hardening. It was found that the strengthening phase of age hardening for AZ91 magnesuim alloy precipitated Mg-Al compound and that the hardness suddenly increased at start of intragranular precipitation after intergranular precipitation nearly became saturated.

일개 대학병원에 내원한 원발성 폐암 환자의 인구학적 및 병리학적 특성

주혜원,강경필,김민근,박민석,임현민,이현경,이성순,이영민,김주인,염호기,최수전,이혁표 인제대학교 2006 仁濟醫學 Vol.27 No.-

Background : Recently, the lung cancer mortality rank first in Korea. The prognosis of lung cancer is not good enough with current treatments and multimodality treatments are required. So we are interested in the characteristics of lung cancer patients for better treatment. Methods : We searched lung cancer patients since 1994. Then we collected the data of primary lung cancer patients about the demographic features, histologic types and diagnotic methods. We divided the total period into 2 haves and specific analysis was tried. Results : 1) Total 850 patients were included. 633 (74.5%) were male and 217 (25.5%) were female. 2) The mean age was 65 ± 11 years old. and the peak age was 7th decades. 3) Squamous cell carcinoma(334/850, 39.3%) was slightly more prevalent than adenocarcinoma(302/850, 35.5%). Conclusion : From these results, we expected that older persons will be diagnosed to have lung cancer and adenocarcinoma will be more dominant histologic type with time.

기계적 합금화에 의한 세라믹 입자 분산 2219 알루미늄 합금의 성질

임수근(Su Geun Lim),관우신(M . Sugamata),김자순일(J . Kaneko) 대한금속재료학회 1991 분말야금 Vol.3 No.-

Lumbar Lordosis of Spinal Stenosis Patients during Intraoperative Prone Positioning

Su-Keon Lee,Seung-Hwan Lee,Kyung-Sub Song,Byung-Moon Park,Sang-Youn Lim,Geun Jang,Beom-Seok Lee,문성환,이환모 대한정형외과학회 2016 Clinics in Orthopedic Surgery Vol.8 No.1

Background: To evaluate the effect of spondylolisthesis on lumbar lordosis on the OSI (Jackson; Orthopaedic Systems Inc.) frame. Restoration of lumbar lordosis is important for maintaining sagittal balance. Physiologic lumbar lordosis has to be gained by intraoperative prone positioning with a hip extension and posterior instrumentation technique. There are some debates about changing lumbar lordosis on the OSI frame after an intraoperative prone position. We evaluated the effect of spondylolisthesis on lumbar lordosis after an intraoperative prone position. Methods: Sixty-seven patients, who underwent spinal fusion at the Department of Orthopaedic Surgery of Gwangmyeong Sungae Hospital between May 2007 and February 2012, were included in this study. The study compared lumbar lordosis on preoperative upright, intraoperative prone and postoperative upright lateral X-rays between the simple stenosis (SS) group and spondylolisthesis group. The average age of patients was 67.86 years old. The average preoperative lordosis was 43.5° (± 14.9°), average intraoperative lordosis was 48.8° (± 13.2°), average postoperative lordosis was 46.5° (± 16.1°) and the average change on the frame was 5.3° (± 10.6°). Results: Among all patients, 24 patients were diagnosed with simple spinal stenosis, 43 patients with spondylolisthesis (29 degenerative spondylolisthesis and 14 isthmic spondylolisthesis). Between the SS group and spondylolisthesis group, preoperative lordosis, intraoperative lordosis and postoperative lordosis were significantly larger in the spondylolisthesis group. The ratio of patients with increased lordosis on the OSI frame compared to preoperative lordosis was significantly higher in the spondylolisthesis group. The risk of increased lordosis on frame was significantly higher in the spondylolisthesis group (odds ratio, 3.325; 95% confidence interval, 1.101 to 10.039; p = 0.033). Conclusions: Intraoperative lumbar lordosis on the OSI frame with a prone position was larger in the SS patients than the spondylolisthesis patients, which also produced a larger postoperative lordosis angle after posterior spinal fusion surgery. An increase in lumbar lordosis on the OSI frame should be considered during posterior spinal fusion surgery, especially in spondylolisthesis patients.

Korean research project on the integrated exposure assessment of hazardous substances for food safety

Lim, Ji-Ae,Kwon, Ho-Jang,Ha, Mina,Kim, Ho,Oh, Se Young,Kim, Jeong Seon,Lee, Sang-Ah,Park, Jung-Duck,Hong, Young-Seoub,Sohn, Seok-Joon,Pyo, Heesoo,Park, Kyung Su,Lee, Kwang-Geun,Kim, Yong Dae,Jun, Sang The Korean Society of Environmental Toxicology 2015 환경독성보건학회지 Vol.30 No.-

Objectives: This survey was designed to conduct the first nationwide dietary exposure assessment on hazardous substances including the intakes of functional food and herbal medicine. In this paper, we introduced the survey design and the results of the dietary exposure status and internal exposure levels of lead (Pb), cadmium (Cd), and mercury (Hg). Methods: We selected 4867 subjects of all ages throughout Korea. We conducted a food survey, dietary survey, biomonitoring, and health survey. Results: Pb and Cd were the highest (median value) in the seaweed ($94.2{\mu}g/kg$ for Pb; $594{\mu}g/kg$ for Cd), and Hg was the highest in the fish ($46.4{\mu}g/kg$). The dietary exposure level (median value) of Pb was $0.14{\mu}g/kg$ body weight (bw)/d, $0.18{\mu}g/kg$ bw/d for Cd, and $0.07{\mu}g/kg$ bw/d for Hg. Those with a blood Pb level of less than $5.00{\mu}g/dL$ (US Centers for Disease Control and Prevention, reference value for those 1 to 5 years of age) were 99.0% of all the subjects. Those with a blood Cd level with less than $0.30{\mu}g/L$ (German Federal Environmental Agency, reference value for non-smoking children) were 24.5%. For those with a blood Hg level with less than $5.00{\mu}g/L$ (human biomonitoring I, references value for children and adults, German Federal Environmental Agency) was 81.0 % of all the subjects. Conclusions: The main dietary exposure of heavy metals occurs through food consumed in a large quantity and high frequency. The blood Hg level and dietary exposure level of Hg were both higher than those in the European Union.

Composite Materials-: SiC 휘스커강화 2024 및 7075 알루미늄합금기 복합재료의 제조와 기계적 특성

임수근,김준수 대한금속재료학회(대한금속학회) 1996 대한금속·재료학회지 Vol.34 No.2

Unidirectionally reinforced Al 2024 and Al 7075 composites with SiC whiskers were fabricated by high pressure infiltration technique and subsequent hot extrusion. The microstructure, age hardening behavior and mechanical properties of the composites were examined. Hot extrusion enabled the unidirectional alignment of whiskers, but substantial amount of whiskers was broken during extrusion. The whisker reinforcement tends to accelerate the age hardening, and decrease the amount of aging, due to the inhomogeneous precipitation of stable phases at the lattice defects in the matrix. The beneficial effect of whisker reinforcement was observed up to 473K. Above 573K, however, the mechanical properties of the composite were comparable to those of the unreinforced alloys, attributable to the enhanced grain boundary sliding due to the fine grain structure formed during hot extrusion.

기계적 합금화에 의한 세라믹 입자분산 2024 알루미늄 합금의 성질

임수근,관우신,김자순일 대한금속재료학회(대한금속학회) 1991 대한금속·재료학회지 Vol.29 No.9

A study has been made of the crystallography and thermal stability of Cu-Zn-Al Shape Memory Alloys. The structure and the phase transformation of the alloys were studied by X-ray diffractometer, electron microscopy and resistivity measurement. The damping characteristics of them were also measured. The Ms temperatures varied from -61℃ to 77℃ with concentration of Zn and Al. The cystallographic structure of the parent phase and martensite was found to be DO₃(or L2₁) and modified 18R(β=88°) respectively. When aged at temperatures ranged from 250 to 350℃, the transformation temperatures were lowered and a maximum hardness was obtained. The aged Cu-26Zn-4.75Al and Cu-21Zn-6Al alloys had the structure of mixture of αand βwhereas the Cu-14.9Zn-8Al alloy had a and r structures. The Cu-14.9Zn-8Al alloy had a considerably higher thermal stability than others.