• Title/Summary/Keyword: 3-axis stage

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Microcrack Development in the Pocheon Granite due to Cyclic Loading (피로하중에 의한 포천화강암의 미세균열 발달특성)

  • 장보안;김영화;김재동;이찬구
    • The Journal of Engineering Geology
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    • v.8 no.3
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    • pp.275-284
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    • 1998
  • Deformation behavior and microcrack development due to uniaxial compressive cyclic loading in the Pocheon granite were investigated using the ultrasonic velocity measurements and the differential strain analysis(DSA). Most microcracks were developed along the direction parallel to the loading axis. Microcracks developed at the early stage of cyclic loading were formed by propagation of pre-existing cracks. Ultrasonic velocity measurement, DSA and measurement of permanent deformation are good tools to represent microcrack development in rock. Since results from each method are slightly different, microcrack development should be interpreted from all three methods. The magnitude of microcracks developed at the early stage of cyclic loading under 80% loading level is twice compared with those under 70% loading level. The highest volumetric crack strain is about 3000, indicating that the Pocheon granite will fail with 0.3% occupation of microcrack in volume.

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Plant Regeneration through Somatic Embryogenesis from Embryogenic Callus of Lacquer Tree (Rhus vernicifera Stokes) (참옻나무(Rhus verniciflua)배발생캘러스로부터 체세포배발생에 의한 식물체 재분화)

  • Kim, Jae-Whune;Lee, Won-Seok;Kwon, Ki-Won;In, Jun-Gyo;Choi, Yong-Eui
    • Journal of Plant Biotechnology
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    • v.30 no.3
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    • pp.275-279
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    • 2003
  • Excised cotyledons and embryo axises of zygotic embryos of Rhus vemicifera were cultured on Murashige and Skoog(MS) medium with various concentrations of 2,4-D. About 3-5% of explants produced callus. Embryogenic callus was preferentially induced from basal parts of embryo axis of zygotic embryos seeds when they were cultured without removal of seed coats. Somatic embryos were developed from embryogenic callus in growth regulator-free medium after 2-3 subcultures on medium with 1.0mg/L 2,4-D and these embryos were matured to cotyledonary stage. Plantlets with well-developed shoots and roots from embryos were obtained on $\frac{1}{4}$MS medium with GA$_{3}$. After acclimatization of plantlets on artificial soil, they were exposed to soil pots.

Ablation rate study using short pulsed laser subjected to Alumina medium (알루미나 세라믹 소재의 초단파 레이저 어블레이션량 연구)

  • Kim, Kyunghan;Park, Jinho
    • Laser Solutions
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    • v.18 no.4
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    • pp.17-22
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    • 2015
  • In this paper, ablation rate of $Al_2O_3$ ceramics by femtosecond laser fluence is derived with experimental method. The automatic three axis linear stage makes laser optics to move with high spatial resolution. With 10 times objective lens, minimal pattern width of $Al_2O_3$ is measured in the focal plane. Ablated surface area is shown as linear tendency increasing number of machining times with various laser power conditions. Machining times is most sensitive condition to control $Al_2O_3$ pattern width. Also, the linear increment of pattern width with laser power change is investigated. In high machining speed, the ablation volume rate is more linear with fluence because pulse overlap is minimized in this condition. Thermal effect to surrounding medium can be minimized and clean laser process without melting zone is possible in high machining speed. Ablation volume rate decelerates as increasing machining times and multiple machining times should be considered to achieve proper ablation width and depth.

The Adenylyl Cyclase Activator Forskolin Increases Influenza Virus Propagation in MDCK Cells by Regulating ERK1/2 Activity

  • Sang-Yeon Lee;Jisun Lee;Hye-Lim Park;Yong-Wook Park;Hun Kim;Jae-Hwan Nam
    • Journal of Microbiology and Biotechnology
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    • v.33 no.12
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    • pp.1576-1586
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    • 2023
  • Vaccination is the most effective method for preventing the spread of the influenza virus. Cell-based influenza vaccines have been developed to overcome the disadvantages of egg-based vaccines and their production efficiency has been previously discussed. In this study, we investigated whether treatment with forskolin (FSK), an adenylyl cyclase activator, affected the output of a cell-based influenza vaccine. We found that FSK increased the propagation of three influenza virus subtypes (A/H1N1/California/4/09, A/H3N2/Mississippi/1/85, and B/Shandong/7/97) in Madin-Darby canine kidney (MDCK) cells. Interestingly, FSK suppressed the growth of MDCK cells. This effect could be a result of protein kinase A (PKA)-Src axis activation, which downregulates extracellular signal-regulated kinase (ERK)1/2 activity and delays cell cycle progression from G1 to S. This delay in cell growth might benefit the binding and entry of the influenza virus in the early stages of viral replication. In contrast, FSK dramatically upregulated ERK1/2 activity via the cAMP-PKA-Raf-1 axis at a late stage of viral replication. Thus, increased ERK1/2 activity might contribute to increased viral ribonucleoprotein export and influenza virus propagation. The increase in viral titer induced by FSK could be explained by the action of cAMP in assisting the entry and binding of the influenza virus. Therefore, FSK addition to cell culture systems could help increase the production efficiency of cell-based vaccines against the influenza virus.

Analysis of Pregnancy-Associated Plasma Protein-A (PAPP-A) in Porcine Neonatal Testis (미성숙 돼지 정소 내에서의 pregnancy-associated plasma protein-A 특성 분석)

  • Lee, W.Y.;Cho, K.H.;Yeo, J.M.;Shin, Y.K.;Park, J.K.
    • Journal of Practical Agriculture & Fisheries Research
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    • v.22 no.1
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    • pp.5-13
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    • 2020
  • The identify of biomarkers in living tissues is useful to understand the characteristics and functions of the cells. Proteins such as protein gene product 9.5, promyelocytic leukemia zinc finger, NANOG, and stage-specific embryonic antigen-1 have been identified as markers for porcine undifferentiated spermatogonia. In this study, the expression of insulin-like growth factor binding proteins (IGFBPs), a newly discovered porcine spermatogonia marker and pregnancy-associated plasma protein-A (PAPP-A), a protein regulator of IGFBPs, were characterized in 5-day-old porcine testis. To analyze the function of IGFBPs, RT-PCR was performed. IGFBP 2, 3, 4, and 6 were detected in porcine spermatogonia and PAPP-A was detected in basement regions in 5day old porcine seminiferous tubules. PAPP-A was not expressed in spermatogonia, but it was expressed in Sertoli cells. These results suggest that the expression of PAPP-A protein in Sertoli cells may regulate the development and differentiation of testicular cells through the IGF axis in porcine neonatal testis.

Alignment System for Display Panel using Edge Feature (에지 특징을 이용한 디스플레이 패널 설비의 얼라인 시스템)

  • Lee, HoHun;Lee, DaeJong;Chun, MyungGeun
    • Journal of the Korean Institute of Intelligent Systems
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    • v.25 no.3
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    • pp.260-265
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    • 2015
  • This paper proposes a alignment system using edge feature. An alignment system obtains the position and orientation of printed circuit board(PCB) or liquid crystal display(LCD) panel through the fiducial marks. Thus, it is the indicator of the system performance how accurate we detect the positions of the fiducial marks in the target image. Edges have the geometrical characteristics such as positions, lengths, and shapes. These features are suitable for finding the marks and have the advantages of lighting variations, model occlusion, as well as variations in scale and angle. The performance of the proposed system is validated through the alignment experiment using an display panel alignment system included X, Y axis, and rotatable stage.

Fine Seek Control of Extended Applicable Range for Optical Disk Drives

  • Ryoo, Jung-Rae;Jin, Kyoung-Bog;Doh, Tae-Young;Chung, Myung-Jin
    • Transactions on Control, Automation and Systems Engineering
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    • v.3 no.3
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    • pp.146-151
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    • 2001
  • Optical disk drive has excellent advantage of random accessibility of which performance is measured by access time. However, due to the increased rotational velocity of the disk and constraints of mechanical structure, two-stage seek algorithm which executes coarse and fine seeks sequentially has been adopted in most commercial optical disk drives. Although the laser spot is moved to a target track by a single seek operation, the limited operation range of the fine actuator restricts the application of the fine seek algorithm below a few hundreds of tracks. Especially, excessive movement of the objective lens causes a failure in generation of track-cross pulse and results in an unstable seek operation. In this paper, a new control algorithm for extending the fine seek range is proposed with an appropriate control structure. The coarse actuator is utilized to reduce the misalignment between the objective lens and the laser beam axis, and the fine actuator is controlled to follow the reference velocity trajectory. The proposed algorithm is applied to a CD-ROM drive to show its feasibility and some experimental results are presented.

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Machining of Repetitive Micro Patterns using Oscillation Micro Milling (진동 마이크로 밀링을 이용한 미세 반복 패턴 가공 기술 연구)

  • Ro, Seung-Kook;Khim, Gyungho;Park, Jong-Kweon
    • Journal of the Korean Society for Precision Engineering
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    • v.31 no.5
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    • pp.381-387
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    • 2014
  • This paper introduces a system to machine micro-sized patterns effectively on surface based on micro-milling process using tools with simultaneous rotation and oscillation, oscillation micro milling. To review the effectiveness of proposed concept, we integrated a micro-spindle supported by active magnetic bearings with a precision 3-axis air bearing stage using double-wedge mechanism, and tested this oscillation milling. Two types of oscillation milling were tested, which are linear oscillation milling with a flat end mill and elliptical oscillation milling with a ball end mill with 0.3 mm of diameter. The spindle was rotating 110 krpm and workpiece was moving constant speed of 2~8 mm/sec during the oscillation milling. As the results, multiple oval shape dimples were generated in regular spacing, and the variation of elliptical motion made different shapes of patterns. The results showed that proposed oscillation milling can be successfully used for machining repeated micro-patterns.

RESEARCH ON THE DRAGON IMAGE IN TURKISH MINIATURE PAINTINGS

  • KIM, KYONG-MI
    • Acta Via Serica
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    • v.3 no.1
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    • pp.119-138
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    • 2018
  • The dragon of the East was an object of worship and an authority to make rain, unlike the West. The dragon image, one of the positively accepted Chinese motifs with the blue-and-white porcelain of the Ming dynasty by the Ottoman Empire in the 16th century, was combined with gigantic saw-edged leaves to create a genre in Saz style. By combining Eastern dragons with plant motifs instead of clouds, dragons were no longer accepted as authority and nobility but as symbols of life and longevity. Unlike Iran and other countries, the image of dragons in Turkish miniature paintings has evolved into a unique style using Turkish calligraphy. The stylistic feature is that a thick black line that gives the impression of calligraphy forms the dragon's back or a huge saz leaf stalk and forms the axis of the screen. Most of the work was black ink drawing, not painting, and partly lightly painted. In the development stage, the dragon appears as a protagonist on the screen of the early works, but the dragon retreats to the latter half and the saz leaves play a leading role on the screen. A common feature in all paintings, whether early or late, is that they have a militant character and create tension on the screen. From the viewpoint of comparative culture, Turkish dragon miniature drawings of the 16thcentury Ottoman period and the Joseon dynasty are somewhat similar in that they are based on calligraphic character and desire for longevity and loyalty, and are drawn according to certain iconic principles.

Liquid-monopropellant Thrusters for the 3-axis Attitude Control of Space Launch Vehicles -Part 2: A Practical Application of Flight-axes/Attitude Control Thrusters to the Space Launch Vehicle and Their Design Development Localization (우주발사체 3축 자세제어용 단일액체추진제 추력기 -Part 2: 비행축/자세제어용 추력기의 우주발사체 적용과 국내 설계개발)

  • Kim, Jeong-Soo;Bae, Dae-Seok;Jung, Hun;Seo, Hang-Seok;Kim, In-Tae
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2011.04a
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    • pp.179-182
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    • 2011
  • A practical application of flight-axes/attitude control thrusters to the space launch vehicle and their design development localization are investigated and analyzed. Hydrazine thrusters are mostly used in a final stage of space launch vehicles on account of its higher specific impulse and reliability necessary for the precise attitude control attaining the orbit insertion with higher accuracy.

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