• Title/Summary/Keyword: Fusion process

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Useful Corrosion - Potential of Magnesium Alloys as Implants

  • Kaya, A. Arslan;Kaya, R. Alper;Witte, Frank;Duygulu, Ozgur
    • Corrosion Science and Technology
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    • v.7 no.3
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    • pp.162-167
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    • 2008
  • Degradable implants have been in use for bone surgery for decades. However, degradable metal implants are one of the new research areas of biomaterials science. Magnesium has good biocompatibility due to its low toxicity, and it is a corroding, i.e. dissolvable, metal. Furthermore, magnesium is needed in human body, and naturally found in bone tissue. There have been some published reports also asserting the potential bone cell activation or bone healing effect of high magnesium ion concentrations. The classic method for achieving intertransverse process fusion involves autogenous iliac crest bone graft. Several investigations have been performed to enhance this type of autograft fusion. However, there is no research which has been undertaken to investigate the efficiency of pure magnesium particles in posterolateral spinal fusion. In this study, corrosion behavior of magnesium metal at the bone interface, the possibility of new bone cell formation and the degree of effectiveness in producing intertransverse process lumbar fusion in a sheep model have been investigated. Cortical bone screws were machined from magnesium alloy AZ31 extruded rod and implanted to hip-bones of sheep via surgery. Three months after surgery, the bone segments carrying these screws were removed from the sacrificed animals. Samples were sectioned to reveal Mg/bone interfaces and investigated using optical microscope, SEM-EDS and radiography. Optical and SEM images showed that there was a significant amount of corrosion on the magnesium screw. The elemental mapping results indicate, due to the presence of calcium and phosphorus elements, that there exists new bone formation at the interface. Furthermore, sixteen sheep were subjected to intertransverse process spinal fusions with pedicle screw fixation at various locations along their spines. Each animal was treated with 5cc autograft bone at one fusion level and 1cc magnesium+5cc autograft bone at the other. Six months after surgery, bone formation was evaluated by gross inspection and palpation, and radiological, histological, scanning electron microscopic and x-ray diffraction analyses. It may be stated that the potential for using useful corrosion of magnesium alloys in medical applications is expected to be significant.

The Effect of Perioperative Radiation Therapy on Spinal Bone Fusion Following Spine Tumor Surgery

  • Kim, Tae-Kyum;Cho, Wonik;Youn, Sang Min;Chang, Ung-Kyu
    • Journal of Korean Neurosurgical Society
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    • v.59 no.6
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    • pp.597-603
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    • 2016
  • Introduction : Perioperative irradiation is often combined with spine tumor surgery. Radiation is known to be detrimental to healing process of bone fusion. We tried to investigate bone fusion rate in spine tumor surgery cases with perioperative radiation therapy (RT) and to analyze significant factors affecting successful bone fusion. Methods : Study cohort was 33 patients who underwent spinal tumor resection and bone graft surgery combined with perioperative RT. Their medical records and radiological data were analyzed retrospectively. The analyzed factors were surgical approach, location of bone graft (anterior vs. posterior), kind of graft (autologous graft vs. allograft), timing of RT (preoperative vs. postoperative), interval of RT from operation in cases of postoperative RT (within 1 month vs. after 1 month) radiation dose (above 38 Gy vs. below 38 Gy) and type of radiation therapy (conventional RT vs. stereotactic radiosurgery). The bone fusion was determined on computed tomography images. Result : Bone fusion was identified in 19 cases (57%). The only significant factors to affect bony fusion was the kind of graft (75% in autograft vs. 41 in allograft, p=0.049). Other factors proved to be insignificant relating to postoperative bone fusion. Regarding time interval of RT and operation in cases of postoperative RT, the time interval was not significant (p=0.101). Conclusion : Spinal fusion surgery which was combined with perioperative RT showed relatively low bone fusion rate (57%). For successful bone fusion, the selection of bone graft was the most important.

Hyper Neutral Beam System for Damage Free Deposition of Indium-Tin Oxide Thin Films at Room Temperature

  • Yoo, Suk-Jae;Kim, Dae-Chul;Kim, Jong-Sik;Oh, Kyoung-Suk;Lee, Bong-Ju;Choi, Soung-Woong;Park, Young-Chun;Jang, Jin-Nyoung;Hong, Mun-Pyo
    • 한국정보디스플레이학회:학술대회논문집
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    • 2007.08a
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    • pp.190-192
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    • 2007
  • A neutral beam system has been developed to produce hyperthermal neutral beams composed of indium, tin, and oxygen atoms. Using these hyper thermal neutral beams with energies in the range of tens of eV, high quality indium-tin oxide (ITO) thin films have been obtained on glass substrates at room temperature. The optical transmittance of the films is higher than 85% at a wavelength of 550 nm and the electrical resistivity is lower than $1{\times}10^{-3}{\Omega}cm$.

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Identification of a Fusion-associated Protein in the Skeletal Myoblast Using Monoclonal Antibody (단일클론항체를 이용한 배양 계배 근원세포의 융합과 연관된 단백질의 확인)

  • Kim, Chons-Rak;Won
    • The Korean Journal of Zoology
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    • v.35 no.1
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    • pp.29-36
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    • 1992
  • The present study describes the production of monoclonal antibodies against cultured chick myoblast to pursue critical proteins in muscle cell fusion. Among a panel of monoclonal antibodies, three, Mll-3H 13, Mll-3Hl8 and Mll-3H35 were inhibited movblast fusion. A single 101-kDa antigen reactive with monoclonal antibody Mll-3H35 was detected by radioimmu-noprecipitation or by immunoblotting. During the course of myogenesis, the level of the protein remarkably decreased as the cells there differentiated. These results suggest that the protein platys a direct role in the process of myoblast fusion mechanism.

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Decision Fusion for Target Identification System (수중 음향 표적 식별 시스템에서의 Decision Fusion)

  • Yoon Gi-Bum;Kim Nam-Hoon;Ko Hanseok
    • Proceedings of the Acoustical Society of Korea Conference
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    • autumn
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    • pp.131-134
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    • 2000
  • 본 논문에서는 각 지역의 수중 음향 센서로부터 중앙의 정보 융합 센터로 전송되어진 동일한 또는 상이한 표적의 Identity 정보들을 종합해 최종적으로 표적의 Identity를 결정하는 Decision Fusion 기법을 다룬다. 기존의 연구는 표적의 속성 정보로부터 정보 융합을 통해 표적의 Identity를 선택하는 기법을 주로 다루고 있다. 그러나 본 논문에서는 기존의 연구보다 한 단계 나아가 선택된 표적의 Identity들로부터 운용자가 가장 합리적인 결정을 내릴 수 있도록 하는 표적의 Identity 결정을 위한 Decision Fusion 기법을 제안한다. 이러한 수중 음향 표적 식별 시스템에서의 Identity Decision Fusion 기법으로 Voting 기법, 센서 정보의 신뢰도를 고려한 Weighted Voting 기법, 그리고 다 기준 의사 결정 기법인 Analytic Hierarchy Process (AHP) 기법을 제안하고 그 성능을 평가한다

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Estimation of the neutron production of KSTAR based on empirical scaling law of the fast ion stored energy and ion density under NBI power and machine size upgrade

  • Kwak, Jong-Gu;Hong, S.C.
    • Nuclear Engineering and Technology
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    • v.54 no.6
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    • pp.2334-2337
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    • 2022
  • Deuterium-tritium reaction is the most promising one in term of the highest nuclear fusion cross-section for the reactor. So it is one of urgent issues to develop materials and components that are simultaneously resistant to high heat flux and high energy neutron flux in realization of the fusion energy. 2.45 MeV neutron production was reported in D-D reaction in KSTAR and regarded as beam-target is the dominant process. The feasibility study of KSTAR to wide area neutron source facility is done in term of D-D and D-T reactions from the empirical scaling law from the mixed fast and thermal stored energy and its projection to cases of heating power upgrade and DT reaction is done.

MOSAICFUSION: MERGING MODALITIES WITH PARTIAL DIFFERENTIAL EQUATION AND DISCRETE COSINE TRANSFORMATION

  • GARGI TRIVEDI;RAJESH SANGHAVI
    • Journal of Applied and Pure Mathematics
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    • v.5 no.5_6
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    • pp.389-406
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    • 2023
  • In the pursuit of enhancing image fusion techniques, this research presents a novel approach for fusing multimodal images, specifically infrared (IR) and visible (VIS) images, utilizing a combination of partial differential equations (PDE) and discrete cosine transformation (DCT). The proposed method seeks to leverage the thermal and structural information provided by IR imaging and the fine-grained details offered by VIS imaging create composite images that are superior in quality and informativeness. Through a meticulous fusion process, which involves PDE-guided fusion, DCT component selection, and weighted combination, the methodology aims to strike a balance that optimally preserves essential features and minimizes artifacts. Rigorous evaluations, both objective and subjective, are conducted to validate the effectiveness of the approach. This research contributes to the ongoing advancement of multimodal image fusion, addressing applications in fields like medical imaging, surveillance, and remote sensing, where the marriage of IR and VIS data is of paramount importance.

A possible role of lipopolysaccharides in the prevention of lysosome0symbiosome fusion as studied by microinjection of an anti-LPS monoclonal antibody (리소솜과 공생낭의 융합저해에서의 Lipopolysaccharide의 역할에 관한 연구)

  • Choi, Eui-Yul
    • Korean Journal of Microbiology
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    • v.32 no.4
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    • pp.280-284
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    • 1994
  • Lack of lysosomal fusion with symbiosomes in symbiont-bearing Amoeba proteus may be due either to the presence of a component in the symbiosome membrane or to the absence of a component needed in the fusion process. Using monoclonal antibody as a probe, lipopolysaccharides were identified as symbiosome-membrane components contributed by symbionts and were found to be exposed on the cytoplasmic side of the membrane. In order to test whether lipopolysaccharides may play a role in the prevention of lysosome-symbiosome fusion, the antilipopolysaccharides antibody was microinjected and processed for double immunostaining in conjuction with anti-lysosome antibody as a lysosome-fusion indicator. Microinjection of the anti-LPS antibody caused symbiosomes to fuse with lysosomes, suggesting that X-bacterial lipopolysaccharides could be 'fusion-preventing' factors.

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Establishment and Application of a Femtosecond-laser Two-photon-polymerization Additive-manufacturing System

  • Li, Shanggeng;Zhang, Shuai;Xie, Mengmeng;Li, Jing;Li, Ning;Yin, Qiang;He, Zhibing;Zhang, Lin
    • Current Optics and Photonics
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    • v.6 no.4
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    • pp.381-391
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    • 2022
  • Two-photon-polymerization additive-manufacturing systems feature high resolution and precision. However, there are few reports on specific methods and possible problems concerning the use of small lasers to independently build such platforms. In this paper, a femtosecond-laser two-photon-polymerization additive-manufacturing system containing an optical unit, control unit, monitoring unit, and testing unit is built using a miniature femtosecond laser, with a detailed building process and corresponding control software that is developed independently. This system has integrated functions of light-spot detection, interface searching, micro-/nanomanufacturing, and performance testing. In addition, possible problems in the processes of platform establishment, resin preparation, and actual polymerization for two-photon-polymerization additive manufacturing are explained specifically, and the causes of these problems analyzed. Moreover, the impacts of different power levels and scanning speeds on the degree of polymerization are compared, and the influence of the magnification of the object lens on the linewidth is analyzed in detail. A qualitative analysis model is established, and the concepts of the threshold broadening and focus narrowing effects are proposed, with their influences and cooperative relation discussed. Besides, a linear structure with micrometer accuracy is manufactured at the millimeter scale.

Image Registration and Fusion between Passive Millimeter Wave Images and Visual Images (수동형 멀리미터파 영상과 가시 영상과의 정합 및 융합에 관한 연구)

  • Lee, Hyoung;Lee, Dong-Su;Yeom, Seok-Won;Son, Jung-Young;Guschin, Vladmir P.;Kim, Shin-Hwan
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.36 no.6C
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    • pp.349-354
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    • 2011
  • Passive millimeter wave imaging has the capability of detecting concealed objects under clothing. Also, passive millimeter imaging can obtain interpretable images under low visibility conditions like rain, fog, smoke, and dust. However, the image quality is often degraded due to low spatial resolution, low signal level, and low temperature resolution. This paper addresses image registration and fusion between passive millimeter images and visual images. The goal of this study is to combine and visualize two different types of information together: human subject's identity and concealed objects. The image registration process is composed of body boundary detection and an affine transform maximizing cross-correlation coefficients of two edge images. The image fusion process comprises three stages: discrete wavelet transform for image decomposition, a fusion rule for merging the coefficients, and the inverse transform for image synthesis. In the experiments, various types of metallic and non-metallic objects such as a knife, gel or liquid type beauty aids and a phone are detected by passive millimeter wave imaging. The registration and fusion process can visualize the meaningful information from two different types of sensors.