• Title/Summary/Keyword: Mixed Core

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Micro-threads of Cross-linked Hyaluronic Acid Hydrogel using a Microfluidic Chip (미세 유체 칩 기반의 히알루론산 미세 실의 제작)

  • Lee, Yun-Kyung;Lee, Kwang-Ho
    • Journal of Biomedical Engineering Research
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    • v.38 no.1
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    • pp.1-8
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    • 2017
  • The successful synthesis of hyaluronic acid micro-threads is very promising approach for the broad application in tissue engineering such as dermal fillers. Because hyaluronic acid has the excellent biocompatibility and ability to maintain the moisture of up to several hundred times its own weight. In order to generate the hyaluronic acid micro-threads in microfluidic system, we employed two-phase flow microfluidic chip to make a rapid synthesis of the hyaluronic acid hydrogel. Hyaluronic acid was mixed with 0.02N NaOH solution and 1, 4-Butanediol diglycidyl ether (BDDE) solution and then injected into core channel. The ethanol was used for the 3-dimensional micro-thread formation in sheath channel. We manipulated the diameter of HA micro-threads using controlling of flow rates in microfluidic chip, and showed the feasibility of immobilization in HA micro-threads with florescent substances. Also, the generated HA micro-threads were evaluated and showed the suitable properties with tensile strength, bending property, and swelling profiles for dermal fillers. As a result, we suggested an innovative method for microfluidic chip-based HA micro-threads which could safely be applied as dermal filler in tissue engineering.

Fluid dynamical characteristics of microencapsulated phase change material slurries (미립잠열슬러리의 유체역학적 특성연구)

  • 이효진;이승우;이재구
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.11 no.4
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    • pp.549-559
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    • 1999
  • An experimental study was peformed to measure the viscosity of microencapsulated PCM slurries as the functions of its concentration and temperature, and also influence to its fluid dynamics. For the viscosity measurement, a rotary type viscometer, which was equipped with temperature control system, was adopted. The slurry was mixed with water and Sodium Lauryl Sulphate as a surfactant by which its suspended particles were dispersed well without the segregation of particles during the experiment. The viscosity was increased as the concentration of MicroPCM particle added. The surfactant increased 5% of the viscosity over the working fluid without particles. Experiments were proceeded by changing parameters such as PCM particles'concentration as well as the temperature of working fluid. As a result, a model to the functions of temperature for the working fluid and its particle concentration is proposed. The proposed model, for which its standard deviation shows 0.8068, is agreed well with the reference's data. The pressure drop was measured by U-tube manometer, and then the friction factor was obtained. It was noted that the pressure drop was not influenced by the state of PCM phase, that is solid or liquid in its core materials at their same concentration. On the other hand, it was described that the pressure drop of the slurry was much increased over the working fluid without particles. A friction factor was placed on a straight line in all working fluids of the laminar flow regardless of existing particles as we expected.

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Mechanical fastening and joining technologies to using multi mixed materials of car body (차체 소재 다변화에 따른 체결 및 접합기술)

  • Kim, Yong;Park, Ki-Young;Kwak, Sung-Bok
    • Journal of Welding and Joining
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    • v.33 no.3
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    • pp.12-18
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    • 2015
  • The ultimate goal of developing body is revealed the "lightweight" at latest EuroCarBody conference 2012 and the most core technology is joining process to make lightweight car body design. Accordingly, in this study, the car body assembly line for the assembly process applies to any introduction, particularly in the assembly of aluminum alloy and composite materials applied by the process for the introductory approached. Process were largely classified by welding (laser, arc, resistance, and friction stir welding), bonding (epoxy bonding) and mechanical fastening (FDS, SPR, Bolting and clinching). Applications for each process issues in the case and the applicable award was presented, based on the absolute strength of the test specimens and joining characteristics for comparative analysis were summarized. Finally, through this paper, we would tried to establish the characteristics of the joint for lightweight structure.

A VLSI DESIGN OF CD SIGNAL PROCESSOR for High-Speed CD-ROM

  • Kim, Jae-Won;Kim, Jae-Seok;Lee, Jaeshin
    • Proceedings of the IEEK Conference
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    • 2002.07b
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    • pp.1296-1299
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    • 2002
  • We implemented a CD signal processor operated on a CAV 48-speed CD-ROM drive into a VLSI. The CD signal processor is a mixed mode monolithic IC including servo-processor, data recovery, data-processor, and I-bit DAC. For servo signal processing, we included a DSP core, while, for CAV mode playback, we adopted a PLL with a wide recovery range. Data processor (DP) was designed to meet the yellow book specification.[2]So, the DP block consists of EFM demodulator, C1/C2 ECC block, audio processor and a block transferring data to an ATAPI chip. A modified Euclid's algorithm was used as a key equation solver for the ECC block To achieve the high-speed decoding, the RS decoder is operated by a pipelined method. Audio playability is increased by playing a CD-DA disc at the speed of 12X or 16X. For this, subcode sync and data are processed in the same way as main data processing. The overall performance of IC is verified by measuring a transfer rate from the innermost area of disc to the outermost area. At 48-speed, the operating frequency is 210 ㎒, and this chip is fabricated by 0.35 um STD90 cell library of Samsung Electronics.

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Chest Wall Lipogranuloma after Hydrogel Implant Rupture: Case Report

  • Park, So Yoon;Han, Boo-Kyung;Cho, Eun Yoon;Bang, Sa-Ik
    • Investigative Magnetic Resonance Imaging
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    • v.19 no.3
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    • pp.191-195
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    • 2015
  • We present a 53-year-old woman with a large chest wall mass in the interpectoral space, which was eventually confirmed as a lipogranuloma resulting from hydrogel implant rupture. Ultrasonography (US) showed reduced implant volume with surrounding peri-implant fluid collection, suggesting the possibility of implant rupture. A heterogeneously hypoechoic mass was found between the pectoralis major and minor muscles adjacent to the ruptured implant. On magnetic resonance imaging (MRI), there was a large mass in the left interpectoral space of the upper inner chest wall. The mass showed slightly high signal intensity (SI) on pre-contrast T1-weighted image (WI) with mixed iso and high SI on T2-WI. The signal of the mass was suppressed using the water suppression technique but not with the fat suppression technique on T2-WI. The mass showed diffuse enhancement upon contrast enhancement. The enhancing kinetics showed persistent enhancement pattern. US-guided core needle biopsy revealed a lipogranuloma and removal confirmed a ruptured PIP hydrogel implant.

A Study on the Effect of a Hippie Fashion on the Bobos Fashion (히피패션이 보보스패션에 미친 영향에 관한 연구)

  • 정은숙;김신우
    • Journal of the Korean Society of Costume
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    • v.52 no.2
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    • pp.45-57
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    • 2002
  • 21th century is evolving from physical to brain-oriented society, and from class oriented society to network society. In the midst of it, bobos is the new enlightened elite group. In depth analyzationon of the beat generation from the 1950's and hippies from the 1960's, which had influenced the bobos, were done to study on such new and core elite group. According to the research, the emerging of bobos was originated and created from the long gone conflict between the beat and bourgeois, and the hippie and the conservative. And this mixed culture of both free-spirited hippie and materialistic yuppies from the 80's is rapidly growing, and they are easily seem from various commercial advertisements, accessories and fashion designs. In addition, the bobo's were targeted by the main designers, and expressed through bohemian luxury and romantic hippie mood. Naive and childish floral prints, paisley prints that were influenced by the hippies, the hair styles from the 80's and washed denims were seen at the collections. However, the symbolism of the 60's defiant fashion styles seem to fade away but remains only as a style. The comparison and analyzation between the fashion of bobos, hidden meaning of those defiant fashion styles and the aesthetics of it are arranged in the following conclusions.

The Development of Fusion Textile Design by Using the Patterns Described in Buncheong Pottery and Mondrian's Works (한국 분청사기 문양과 몬드리안 작품을 이용한 퓨전 직물디자인 개발)

  • Jung, Jin-Soun
    • Fashion & Textile Research Journal
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    • v.8 no.5
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    • pp.505-512
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    • 2006
  • Today a new culture called fusion has been forming. And it is spreading at an alarming rate in our society. When people talk about the character of Korean beauty and Korean culture, they speak taking pottery as an example. We can speak that the pottery is a core of culture which represent our people. And I think its pattern can be a good material for fusion. Also, among many Western artists, Mondrian is an unique painter who is to do with our culture. So, in this study, I chose the patterns described in Buncheong pottery and the Mondrian's works for the development of fusion textile design. Patterns expressed on Buncheong pottery are, for the most part, abstract patterns simplified the shape of object. And the Mondrian's works is the geometrical abstract painting be made by vertical and horizon. Using those I intend to develop the fusion textile designs which mixed Oriental culture and Western culture. Also, I intended to simulate them on ties and clothes and present the possibility of culture merchandise development. The reasons for doing so to let other peoples of the world, know about our excellent culture.

Fabrication of Artificial Bone through the Imitation of human bone

  • Jang, Dong-U;Sakar, Swapan Kumar;Kim, Min-Sung;Song, Ho-Yeon;Min, Young-Gi;Lee, Byong-Taek
    • Proceedings of the Materials Research Society of Korea Conference
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    • 2010.05a
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    • pp.41.2-41.2
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    • 2010
  • In this work, HAp-(t-ZrO2) ceramic composites of biomimic artificial bone were fabricated by multi-extrusion process in order to replace nature bone. HAp-(t-ZrO2) and graphite powders were mixed separately with ethylene vinyl acetate (EVA) and stearic acid using shear mixer. Extruded HAp-(t-ZrO2) filaments and carbon filaments were arranged in the die to fabricate the first pass filament. The first pass filaments were arranged in the same die with a central carbon core for making the space for spongy bone. Burning out and sintering processes were performed to remove the binder and lubricant. The microstructure channel diameter was researched around $300{\mu}m$. Microstructure analysis was carried out by OM, SEM, and $\mu$-CT. Compressive strength was investigated for the artificial bone. Some preliminary bio-compatibility test was evaluated.

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Raffles City in Hangzhou China -The Engineering of a 'Vertical City' of Vibrant Waves-

  • Wang, Aaron J.
    • International Journal of High-Rise Buildings
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    • v.6 no.1
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    • pp.33-47
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    • 2017
  • This mixed-use Raffles City (RCH) development is located near the Qiantang River in Hangzhou, the capital of Zhejiang province, located southwest of Shanghai, China. The project incorporates retail, offices, housing, and hotel facilities and marks the site of a cultural landscape within the Quianjiang New Town Area. The project is composed of two 250-meter-tall twisting towers with a form of vibrant waves, along with a commercial podium and three stories of basement car parking. It reaches a height of 60 stories, presenting views both to and from the Qiantang River and West Lake areas, with a total floor area of almost 400,000 square meters. A composite moment frame plus concrete core structural system was adopted for the tower structures. Concrete filled steel tubular (CFT) columns together with steel reinforced concrete (SRC) beams form the outer moment frame of the towers' structure. The internal slabs and floor beams are of reinforced concrete. This paper presents the engineering design and construction of this highly complex project. Through comprehensive discussion and careful elaboration, some conclusions are reached, which serve as a reference guide for the design and construction of similar free-form, hybrid, mix-use buildings.

Simulations of the Unsteady Viscous Flow Around an Impulsively Started Cylinder Using Improved Vortex Particle Method (개선된 입자와법을 이용한 급 출발하는 실린더 주위의 비정상 점성 유동 시뮬레이션)

  • Jin, Dong-Sik;Lee, Sang-Hwan;Lee, Ju-Hee
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.24 no.5
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    • pp.733-743
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    • 2000
  • We solve the integral representation of the Navier-Stokes equations in a lagrangian view by tracking the particles, which have vortex strengths. We simulate the unsteady viscous flow around an impulsively started cylinder using the vortex particle method. Particles are advanced via the Biot-Savart law for a lagrangian evolution of particles. The particle strength is modified based on the scheme of particle strength exchange. The solid boundary satisfies the no-slip boundary condition by the vorticity generation algorithm. We newly modify the diffusion scheme and the boundary condition for simulating an unsteady flow efficiently. To save the computation time, we propose the mixed scheme of particle strength exchange and core expansion. We also use a lot of panels to ignore the curvature of the cylinder, and not to solve the evaluation of the surface density. Results are compared to those from other theoretical and experimental works.