• 제목/요약/키워드: PNU

검색결과 322건 처리시간 0.03초

KMPR을 이용한 다층구조물 제작 및 전해도금을 이용한 니켈몰드 제작 (Fabrication of the multi-layer structure and Nickel mold with electroforming using KMPR)

  • 황성진;정필구;고정상;고종수;정임덕;김인곤
    • 한국정밀공학회:학술대회논문집
    • /
    • 한국정밀공학회 2006년도 춘계학술대회 논문집
    • /
    • pp.143-144
    • /
    • 2006
  • In this paper, we proposed XP KMPR-1050 negative tone resist to replace SU-8 resist for multi-layer micro-structures and thick plating mold fabrication using UV-LIGA process. XP KMPR resist proposed in this paper can be easily striped using a common stripping solution such as NMP without damage of micro-structure. The conditions for the fabrication of XP KMPR micro-structure were optimized by adjustment of exposure and post-exposure bake(PEB). The $140{\mu}m$ -thick and an aspect ratio at least 10 micro-structure and multi-layer structures were successfully fabricated through the process conditions. Through-mold electroplating and PR striping of XP KMPR has been successfully demonstrated.

  • PDF

대학도서관에서의 고전자료 개발방안 -부산대학교 도서관을 중심으로- (The Development Program of the Collection for Korean Classical Materials in the University Library - With emphasis on the library of Pusan National University)

  • 송정숙
    • 한국문헌정보학회지
    • /
    • 제25권
    • /
    • pp.215-232
    • /
    • 1993
  • The Long-Term Development Plan of the Pusan National University(PNU) has announced on 1991 in order to reach its roles and levels as an University with international standards, a Graduate School research-oriented and a core university in its community through accomplishment of this Plan. University libraries would be planned to support their universities' goals. Therefore the Library of PNU is facing on the task for supporting the Plan. The Collection for Korean Classical Materials (CKCM) is not limited in Korean Literature, Korean History, Korean Philosophy fields but covered the academic fields except a hightech science : Humanities, social science. pure science, applied science and arts etc. However, the Library of PNU does not have the organization, special librarian and budget for CKCM. Under this notion organization, budget and librarian for the collection would be followed. The CKCM contains the original editions, photography editions, copied issues. microform reproductions with comprehensive subjects in the fields of studies. Especially for the collection of treasure books the role of the Library of PNU induce to open individuals' collections or families' collections to public through the Library. The equipments for preserving rare books and treasure books are the conditioners for humidity and temperature, automatic extinguishment system. The reference materials, copy machine and reading room are requested for the user service of CKCM. The materials would be one of the most important thing in study and research. Therefore the Library of PNU need to pay attention to develop and preserve CKCM.

  • PDF

펄스파워를 이용한 전압 및 주파수 가변에 의한 고효율 RUST (녹) 제거 특성에 대한 연구 (Characteristics of high-efficiency rust removal by adjusting variable frequency and voltage charging using the Pulsed Power system)

  • 송우정;김수원;전진안;정종한;김휘영;김희제
    • 한국전기전자재료학회:학술대회논문집
    • /
    • 한국전기전자재료학회 2002년도 춘계합동학술대회 논문집
    • /
    • pp.180-183
    • /
    • 2002
  • The pulsed power system was widely making use good of many industrial and environments. The pulse generator generally required for short pulse duration and high peak value was forced to consider its volume and economy. In this paper, this system is designed and fabricated which has a compact size of pulse generator with switched MOSFET. We have studied the removal of rust material using Arc discharging. It have tested their characteristics by adjusting variable voltage charging and pulse repetition rate. As a result, We can eliminate rust materials with this device.

  • PDF

초고속 스핀들에 의한 마이크로 엔드밀링의 가공특성에 관한 연구 (A Study on the Machining Characteristics for Micro Endmilling by using Ultrahigh-Speed Air Turbine Spindle)

  • 권동희;강익수;김전하;강명창;김정석
    • 한국정밀공학회:학술대회논문집
    • /
    • 한국정밀공학회 2005년도 추계학술대회 논문집
    • /
    • pp.598-603
    • /
    • 2005
  • Recently, the advanced industries using micro parts are rapidly growing. The appearance of ultra-precision feed mechanism and the development of control system make it possible to process parts in sub millimeter scale by mechanical methods. Micro endmilling is one of the prominent technology that has wide spectrum of application field ranging from macro parts to micro products. So, micro stairs have been trying to cut by using high revolution air turbine spindle and micro-endmill, and studying for magnitude of cutting force. This investigation deals removal characteristics of burr generated by micro endmilling process. Also, decreasing of burr is significant problem in making smooth and precise parts in micro endmilling. In micro endmilling, the material removal rate(MRR) and cutting forces are very small. This paper presents an investigation on the machining characteristics for micro stairs by using ultrahigh-speed air turbine spindle in machining.

  • PDF

CMP 결과에 영향을 미치는 열적거동 특성에 관한 연구 (Investigation of Thermal Behavior Characteristic in Chemical Mechanical Polishing Performance)

  • 정영석;김형재;최재영;김구연;정해도
    • 한국전기전자재료학회:학술대회논문집
    • /
    • 한국전기전자재료학회 2004년도 하계학술대회 논문집 Vol.5 No.2
    • /
    • pp.1283-1287
    • /
    • 2004
  • The design rules are being more strict with requirement of operation speed and development of IC industry. For this reason, required minimum line-width has been narrowed under sub-micron region. As the length of minimum line-width is narrowed, local and global planarization are being prominent. CMP(Chemical-Mechanical Polishing), one of the planarizarion technology, is a process which polishes with the ascent of chemical reaction and relative velocity between pad and wafer without surface defects. CMP is performed with a complex interaction among many factors, how CMP has an interaction with such factors is not evident. Accordingly, the studies on this are still carrying out. Therefore, an examination of the CMP phenomena and an accurate understanding of compositive factors are urgently needed. In this paper, we will consider of the relations between the effects of temperature which influences many factors having an effect on polishing results and the characteristics of CMP in order to understand and estimate the influence of temperature. Then, through the interaction of shown temperature and polishing result, we could expect to boost fundamental understanding on complex CMP phenomena.

  • PDF

PIV 측정 및 수치해석을 이용한 구강암 수술에 따른 기도 형상 내 유동 특성 (Flow Characteristics in a Human Airway model for Oral Cancer Surgery by PIV Experiment and Numerical Simulation)

  • 홍현지;안세현;서희림;송재민;염은섭
    • 한국가시화정보학회지
    • /
    • 제19권3호
    • /
    • pp.115-122
    • /
    • 2021
  • Oral cancer surgery typically consists of resection of lesion, neck dissection and reconstruction, and it has an impact on the position of hyoid bone. Therefore, morphological change of airway can occur since the geometric parameter of airway is correlated with the hyoid bone. Airflow is affected by geometry of the airway. In this study, flow characteristics were compared between pre- and post-surgery models by both particle image velocimetry (PIV) and numerical simulation. 3D model of upper airway was reconstructed based on CT data. Velocity is accelerated by the reduced channel area, and vortex and recirculation region are observed in pre- and post-surgery models. For the post-surgery model, high pressure distribution is developed by significantly decreased hydraulic diameter, and the longitudinal flow stream is also interrupted.

냉장고 팬 모듈의 물빠짐 구멍 주변 유동 특성 검증 (Flow characteristics validation around drain hole of fan module in refrigerator)

  • 판진싱;이수환;서희림;김동우;염은섭
    • 한국가시화정보학회지
    • /
    • 제20권3호
    • /
    • pp.102-108
    • /
    • 2022
  • In the fan module of the intercooling refrigerator, a drain hole structure was designed for stable drainage of defrost water. However, the airflow passing through the drain hole can disturb flow features around the evaporator. Since this backflow leads to an increase in flow loss, the accurate experimental and numerical analyses are important to understand the flow characteristics around the fan module. Considering the complex geometry around the fan module, three different turbulence models (Standard k-ε model, SST k-ω model, Reynolds stress model) were used in computational fluid dynamics (CFD) analysis. According to the quantitative and qualitative comparison results, the Standard k-ε model was most suitable for the research object. High-accuracy results well match with the experiment result and overcome the limitation of the experiment setup. The method used in this study can be applied to a similar research object with an orifice outflow driven by a rotating blade.

김치 유산균 Starter를 이용한 김치의 발효 특성 및 기능성 증진 효과 (Fermentation Properties and Increased Health Functionality of Kimchi by Kimchi Lactic Acid Bacteria Starters)

  • 봉연주;정지강;박건영
    • 한국식품영양과학회지
    • /
    • 제42권11호
    • /
    • pp.1717-1726
    • /
    • 2013
  • 본 연구에서는 김치 유산균 starter의 사용이 김치의 품질특성과 건강기능성에 미치는 영향을 확인하고자 single starter 김치(Lb. plantarum pnuK, Lb. plantarum 3099K, Leu. mesenteroides pnuK), mixed starter 김치(Lb. plantarum pnu/Leu. mesenteroides pnuK, Lb. plantarum 3099/Leu. mesenteroides pnuK), 자연 발효 김치(NK)를 제조하여 $15^{\circ}C$에서 6일간 발효하며 실험하였다. pH 및 산도는 발효 초기에는 차이가 없었으나 발효 2일부터 starter 접종 김치에서 빠른 변화를 보였다. 총호기성 세균과 Lactobacillus sp.는 발효가 진행될수록 비슷하게 증가하였으나 Leuconostoc sp.는 Leu. mesenteroides를 starter로 접종한 김치에서 높게 나타났다. 관능검사 결과 starter를 첨가한 김치에서 관능적 만족도가 높게 나타났으며, 혼합 starter 김치에서 만족도가 더 높았다. DPPH 및 hydroxyl radical 소거능 측정 결과, starter를 첨가한 김치에서 높은 항산화 효과를 보였다. MTT assay 결과, HCT-116 및 HT-29 세포에서 NK는 각각 63.4, 51.9%를 나타내었고 Lb. plantarum pnuK는 각각 77.1, 68.8%의 암세포 성장 저해율을 보였다. 따라서 starter 첨가 시 항산화 및 항암효과가 증가되며, 단일 starter 김치가 혼합 starter 김치보다 높은 기능성을 가지는 것으로 나타났다. 그중 새로 분리 동정된 Lb. plantarum pnu를 이용한 김치에서의 높은 대장암 세포 성장억제 효과를 확인하였다. Apoptosis 유도에 관련된 Bcl-2 및 Bax, 종양 억제에 관련된 p53 및 p21, 염증에 관련된 iNOS 및 COX-2 유전자 발현은 starter 첨가 김치에서 자연발효 김치보다 모두 apoptosis 유도 작용과 염증 및 종양을 억제하는 효과가 높게 나타났다. 가장 높은 효과를 보인 것은 Lb. plantarum pnuK이었으며 단일 starter 김치에서 혼합 starter 김치보다 효과가 높았다. 이상의 결과로 starter를 이용해 관능적 품질이 우수하고 기능성이 증진된 김치를 제조할 수 있을 것으로 기대된다.

UV-Vaccum Casting의 최적 공정 변수 선정 (The Selection of Optimal Process Variables in UV-Vacuum Casting)

  • 김태완;우승목;이석
    • 한국정밀공학회:학술대회논문집
    • /
    • 한국정밀공학회 2000년도 추계학술대회 논문집
    • /
    • pp.453-456
    • /
    • 2000
  • This paper presents experimental results on selecting optimal process parameters for UV-Vaccum casting. The UV-Vacuum casting is a relatively new process that allows very rapid mold preparation and part duplication via UV curing. Effect of various process variables such as pressure and temperature on mold strength and part accuracy was evaluated by using Taguchi method.

  • PDF

펌프-밸브 시스템의 DES 접근론적 Failure Diagnosis (DES Approach Failure Diagnosis of Pump-valve System)

  • 손형일;김기웅;이석
    • 한국정밀공학회:학술대회논문집
    • /
    • 한국정밀공학회 2000년도 춘계학술대회 논문집
    • /
    • pp.643-646
    • /
    • 2000
  • As many industrial systems become more complex, it becomes extremely difficult to diagnose the cause of failures. This paper presents a failure diagnosis approach based on discrete event system theory. In particular, the approach is a hybrid of event-based and state-based ones leading to a simpler failure diagnoser with supervisory control capability. The design procedure is presented along with a pump-valve system as an example.

  • PDF