코로나 플라즈마 처리에 의한 HDPE 표면의 개질에 관한 연구

최진숙,전종탁,정봉규,이근대,문명준,이종무 釜慶大學校 2001 釜慶大學校 論文集 Vol.6 No.-

We are able to generate the stable plasma in open air and nitrogen using a corona plasma treatment system(CPTS) with a high voltage. This was applied to treat the surface of rather non-polar HDPE(High Density Polyethylene) intended for the improvement of adhesion of over-coated layers such as coatings, printing inks. The surface tension of HDPE was significantly improved by the CPTS. The characteristics of surface layer were evaluated by means of contact angle measurement, ATR-FT/IR spectroscopy, and it was found that functional groups were introduced into the surface layer of the HDPE. The use of nitrogen was increased the surface tension of the HDPE from 33.8 mJ/m^2 to 66.56 mJ/m^2, and highly effective method of HDPE surface modification could be realized.

RT-LAMP를 이용한 콩황화일반모자이크바이러스의 진단

배대현, 이영훈, 김봉섭, 윤영남, 강범규, 최만수, 구성철, 김현태, 윤홍태, 이수헌, 백인열 忠北大學校 農業科學硏究所 2014 農業科學硏究 Vol.30 No.2

Soybean yellow common mosaic virus (SYCMV) has been recently reported, it has been occurred a lot with Soybean mosaic virus (SMV) and Soybean yellow mottle mosaic virus (SYMMV) in soybean field. SYCMV belongs to genus of Sobemovirus and induced viral symptoms with yellowing, mottle and mosaic. A reverse transcription loop-mediated isothermal amplification (RT-LAMP) method allowed one-step detection of gene amplification by simple procedure and needed only a simple incubator for isothermal template. This RT-LAMP method allowed direct detection of RNA from virus-infected plants without thermal cycling and gel electrophoresis. In this study, we designed RT-LAMP primers named SYCML-F3/B3/FIP/BIP from coat protein gene sequence of SYCMV. After the reaction of RTLAMP, products were identified by electrophoresis and with the detective fluorescent dye, SYBR Green I. under daylight and UV light. Optimal reaction condition was at 63 for 60min and the primers of RTLAMP showed the specificity for only SYCMV tested in this study.

pH別 Auxin 處理가 林木의 發根에 미치는 影響(Ⅰ) : 서양측백의 揷木發根을 中心으로 Focus on the Rooting of Cuttings of Thuja occidentalis L.

高大植,崔萬峯,鄭鎭澈 全北大學校 1976 論文集 Vol.18 No.-

This study was on investigation of cuttings after 24 hrs. treatment of IBA 20ppm solution of 10 stage pH level, in order to promote rooting of cuttings of Thuja occidentalis L. The results are summarized as follows; 1. Different pH values of auxin solution for rooting promotion of cuttings were significantly influential in rooting. 2. In the cutting collected from 8-years old Thuja occidentalis L., very good results were obtained from the pH 6.0-6.5 level of 20 ppm IBA solution, good results from the pH 5.5 and pH 7 level, and poor results from the pH level near strong acid. 3. In the development of rooting system, average rooting numbers, rooted lengths and rooted weights were developed in proportion to the rooting ratio. 4. Rooting portions were observed with the naked eye to develop in formed callus and epidermis tissue, in epidermis tissue above formed callus, and in epidermis tissue above portion without formed callus. Color of callus portion was reddish-brown.

고주파 모터 내장형 주축의 냉각특성 해석

김수태,최대봉 한국공작기계학회 2002 한국공작기계학회 춘계학술대회논문집 Vol.2002 No.-

Cooling characteristics for the three type spindles with high frequency motor are studied. For the analysis, three dimensional models are built considering heat transfer characteristics such as natural and forced convection coefficients. Unsteady-state temperature distributions and thermal deformations according to the cooling conditions are analyzed by using the finite element method.

연삭기용 자동 밸런싱 장치의 설계 및 평가

장홍석,최대봉,황주호,홍준희 한국공작기계학회 2001 한국공작기계학회 춘계학술대회논문집 Vol.2001 No.-

The balance of high speed spindle system with high precision rotation like grinding machine is very important. Traditionally, we use trial and error method to balance the spindle. It takes much time. So we are developing the automatic balancing equipment being used in the grinding machine. The balancing head we develop is wireless. It will be used high-speed grinding machine. We use influence coefficient method to control the automatic balancer. Experiments are based on automatic and manual balancing. We perform test of the vibration filter. It helps to remove noise. The filter and experiments with automatic balancing controller show that automatic balancing control can be successfully achieved with the quick response and good stability characteristics.

에어-오일 윤활에 의한 공작기계 주축계의 고속화연구

朴京鎬,崔大奉,金洙泰 國立 昌原大學校 産業技術硏究所 1992 産技硏論文集 Vol.6 No.-

According to the development of cutting tools, the high speed of machine tool's spindle is needed, and the demands for the precision machining, the improvement of light materials' productivity and etc. are increased. The spindle of machine tool with the maximum speed, ??·N, has lately been used and that over ??·N has been studied in advanced countries. In the country, the study on this field is needed because the spindle with the speed,??·N, is used up to now. Therefore, the study is carried out for the high speed spindle design, the lubrication system and the development of spindle unit.

공작기계 주축계의 오일에어윤활특성에 관한 연구

김석일,최대봉 한국항공대학 항공문제연구소 1992 航空問題硏究所 硏究誌 Vol.2 No.-

최근 오일에어윤활방법은 고속용 구름베어링에 대한 효과적인 윤활방법의 하나로서 많은 주목을 받고 있다. 본 연구에서는 공작기계의 생산성과 가공정밀도를 향상시키기 위한 노력의 일환으로 오일에어윤활방법에 기초를 둔 공작기계용 고속주축계를 개발하였다. 그리고 개발된 고속주축계의 성능을 평가하기 위한 일련의 윤활실험을 수행하였다. 특히 공작기계 주축계의 고속화에서 고려해야 할 윤활조건과 구조설계조건을 도출하기 위해서 공급유량, 주축회전수, 그리고 주축계의 구조가 베어링의 온도상승, 베어링의 온도분포, 그리고 주축계의 마찰토오크에 미치는 영향을 고찰하였다. Recently the oil-air lubrication method has attracted special interest as one of the effective lubrication methods for a high-speed rolling bearing. In this study, the high speed spindle system of machine tools based on the oil-air lubrication method is developed to reduce the machining time and to improve the machining accuracy. And a lubrication experiment for evaluating the performance of the developed spindle system is carried out. Especially, in order to establish the lubrication and structural design conditions related to the development of a high-speed spindle system, the effects of oil supply rate, rotational spindle speed and spindle system structure on the bearing temperature rise, bearing temperature distribution and frictional torque are investigated.

측뇌실내 종괴의 감별진단 및 수술적 치료

김동규,김봉수,이상형,심기범,왕규창,정희원,김현집,조병규,최길수,한대희 대한신경외과학회 1993 Journal of Korean neurosurgical society Vol.22 No.2

We present a series of 42 patients with the lateral ventricular mass lesions who underwent operative removal between 1979 and 1992 at the Seoul National University Hospital. These lesions included 29 tumors, 10 benign cysts and 3 arteriovenous malformations. There were 20 lesions in the trigone, 14 in the frontal horn, 6 in the body, and 2 in the temporal horn. Together with the age of the patient, the location in the lateral ventricle and the CT or MR patterns, the range of the differential diagnosis of the lesions can be narrowed. The mass were removed by various surgical approaches ; 11 by the middle frontal gyrus, 10 by the superior parieto-occipital, 13 by the middle temporal gyrus, 4 by the anterior transcallosal, 2 by the posterior transcallosal and 3 by the combined approaches. The superior parieto-occipital approach left postoperative morbidities in 64% and other approaches in 20 to 25% of the cases. These morbidities included hemiparesis, hemianopsia, aphasia, memory distubance and seizure. Most hydrocephalus disappeared without the shunting procedure after removal of the lateral ventricular mass. The high frequency of postoperative complications in the superior parieto-occpital approach require meticulous consideration in the selection of this approach.

열전달을 고려한 고속 주축계의 열특성 해석에 관한 연구

백경근,김수태,최대봉,김태형 한국공작기계학회 2000 한국공작기계학회 추계학술대회논문집 Vol.2000 No.-

Unsteady-state temperature distributions and thermal deformations in high speed spindle are studied. For the analysis, three dimensional model is built considering heat transfer characteristics such as natural and forced convection coefficients Temperature distributions and thermal deformations are analyzed by using the finite element method. Results of analysis are compared with the measured data.

예압과 냉각방식에 따른 고속주축의 온도분포 및 열변형 해석

김수태,김재실,최대봉,김진한,정동수 국립7개대학공동논문집간행위원회 2005 공업기술연구 Vol.5 No.-

The use of high speed motor spindle is increasing for high speed machine tools recently. The important problem in the high speed spindles is to reduce and minimize the thermal effect by the motor and ball bearings. Thermal characteristics according to the bearing preload, hollow shaft and oil jacket cooling are studied for the spindle with the oil mist lubrication and high frequency motor. In this study, temperature distribution and thermal deformation are analyzed by using the numerical method This results show that temperature distribution and thermal deformation of the high speed spindle system can be estimated reasonably by using the three dimensional model through the finite element method and support thermal optimization and more effective cooling method.