• Title/Summary/Keyword: Fracture-separation

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Reconstruction of Medial Orbital Wall Fractures without Subperiosteal Dissection: The "Push-Out" Technique

  • Kim, Yong-Ha;Lee, Jin Ho;Park, Youngsoo;Kim, Sung-Eun;Chung, Kyu-Jin;Lee, Jun-Ho;Kim, Tae Gon
    • Archives of Plastic Surgery
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    • v.44 no.6
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    • pp.496-501
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    • 2017
  • Background Various surgical methods for repairing medial orbital wall fractures have been introduced. The conventional technique requires total separation of the displaced orbital bones from the orbital soft tissues. However, subperiosteal dissection around the fracture can cause additional damage. The aim of the present study is to introduce a method of reconstructing medial orbital wall fractures without subperiosteal dissection named the "push-out" technique. Methods Six patients with post-traumatic enophthalmos resulting from an old medial orbital wall fracture and 10 patients with an acute medial orbital wall fracture were included. All were treated with the push-out technique. Postoperative computed tomography (CT) was performed to assess the correct positioning of the implants. The Hertel scale and a comparison between preoperative and postoperative orbital volume were used to assess the surgical results. Results Restoration of the normal orbital cavity shape was confirmed by examining the postoperative CT scans. In the old fracture group, the median orbital volume of the fractured side was $29.22cm^3$ preoperatively, and significantly improved postoperatively to a value of $25.13cm^3$. In the acute fracture group, the median orbital volume of the fractured side was $28.73cm^3$ preoperatively, and significantly improved postoperatively to a value of $24.90cm^3$. Differences on the Hertel scale also improved, from 2.13 mm preoperatively to 0.25 mm postoperatively in the old fracture group and from 1.67 mm preoperatively to 0.33 mm postoperatively in the acute fracture group. Conclusions The push-out technique can be considered a good alternative choice for old medial orbital wall fractures with posttraumatic enophthalmos, acute medial orbital wall fractures including large fractured bone segments, and single-hinged greenstick fractures.

Separation of Single-Walled Carbon Nanotubes by Length and Diameter (단일벽 탄소 나노튜브의 길이와 지름에 따른 분류)

  • Oh Young-Seok;Lee Dock-Jin;Chang Yyun-Seok;Choi Jae-Boong;Kim Young-Jin;Baik Seung-Hyun
    • Journal of the Korean Society for Precision Engineering
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    • v.23 no.3 s.180
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    • pp.171-178
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    • 2006
  • The sonication mettled is widely used with surfactants to suspend individual single-walled carbon nanotubes in solution, and it is well known that sonication-induced tube cutting occurs. Recently, it is found out that ultrasonicated nanotubes yield simultaneous separation by tube length and diameter. Nanotubes that have been cut shortest possess the greatest enrichments of large-diameter species. In this study, single-walled carbon nanotubes are cut using a ball milling method. Similar fracture behavior is observed fur the ball milled nanotubes: i.e., large diameter tubes are cut shorter. The ability to separate carbon nanotubes by diameter and length will contribute to tile development of nanotube-based applications.

The Study for Fracture Parameter J in Rubber-Cord Composites with a Penny-Shaped Crack on Cord-End (고무-코드 복합체 코드-끝 균열에 대한 파괴역학적 매개변수 J에 관한 연구)

  • Yang, Kyeong-Jin;Kang, Ki-Ju
    • Proceedings of the KSME Conference
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    • 2000.04a
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    • pp.304-308
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    • 2000
  • In this work, an equation of J-integral for a penny-shaped crack at the end of the cord embedded in rubber matrix is proposed. The dimensional analysis is applied to derived to the equation of J-integral. We assume that the energy Parameter J is separated into the deformation and the geometry function, and which is proved using by separation parameter.

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Diagnostic Value of Computed Tomography in Acetabular Fracture (관골구 골절에서의 전산화단층촬영술의 진단적 가치)

  • Kim, Sun-Yong;Park, Bok-Hwan;Ihn, Joo-Chul
    • Journal of Yeungnam Medical Science
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    • v.5 no.1
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    • pp.43-48
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    • 1988
  • We retrospectively analysed 22 patients pelvic CT, in whom the acetabular fracture were suspected in plain film. And compared and analysed the computed tomogram findings and plain radiographic findings. The results were as follows. CT enables better evaluation of shape, extent, and degree of separation of fragment. CT was helpful in detecting the combinded fracture and soft tissue injuries. CT showed intraarticular loose bodies, which were invisible on plain film. In patients with pelvic trauma, no necessary changing position during CT examination. CT was useful demonstrates the remnant of intraarticular osseous fragment and adequacy of reduction after surgery.

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Three dimensional finite element simulations of fracture tests using the Craft concrete model

  • Jefferson, A.D.;Barr, B.I.G.;Bennett, T.;Hee, S.C.
    • Computers and Concrete
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    • v.1 no.3
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    • pp.261-284
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    • 2004
  • Two enhancements to a recently developed plastic-damage-contact model for concrete are presented. The model itself, which uses planes of degradation that can undergo damage and separation but that can regain contact according to a contact law, is described. The first enhancement is a new damage evolution function which provides a completely smooth transition from the undamaged to the damaged state and from pre-peak to post-peak regions. The second is an improved contact function that governs the potential degree of contact with increasing opening on a crack plane. The use of a damage evolution function with a pre-peak has implications for the consistent tangent matrix/stress recovery algorithm developed for the model implementation, and amendments to this algorithm to accommodate the new function are described. A series of unpublished experimental tests on notched specimens undertaken in Cardiff in the mid 1990s are then described. These include notched beam tests as well as prismatic and cylindrical torsion tests. The tests are then considered in three dimensional finite element analyses using the modified Craft model implemented in the finite element program LUSAS. Comparisons between experimental and numerical data show reasonable agreement except that the numerical simulations do not fully describe the latter stages of the softening responses for the torsion examples. Finally, it is concluded that the torsion tests described provide useful benchmark examples for the validation of three-dimensional numerical models for concrete.

Microstructure and Processing of Bioactive Ceramic Composites as Dental Implants (치과 임플란트용 bioactive 세라믹 복합재료의 제조와 미세조직)

  • Kim, Bu-Sob
    • Journal of Technologic Dentistry
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    • v.25 no.1
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    • pp.21-28
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    • 2003
  • The purpose of this study was to process bio-active glass ceramic composite, reinforced with sapphire fibers, by hot press. Also to study the interface of the matrix and the sapphire fiber, and the mechanical properties. Glass raw materials melted in Pt crucible at 1300$^{\circ}C$ during 3.5 hours. The melt was crushed in ball mill and then crushed material, ground and sieved to $<40{\beta}{\mu}m$. Sapphire fibers cut (30mm) and aligned. Powder and fibers hot pressed. The micrographs show good bonding between the matrix and the fiber and no porosity in the glass matrix. This means ideal fracture phenomena. Glass is fractured before the fiber. This is indication of good fracture strength. EDXS showing aluminum rich phase and crystalline phase. Bright field image of the matrix showing crystalline phase. Also diffraction pattern of TEM showing the crystalline phase and more than one phase. Strength of the samples was determined by 3 point bend testing. Strength of the 10vol% sample was approximately 69MPa, while strength of the control sample is 35MPa. Conclusions through this study as follow: 1. Micrographs show no porosity in the glass matrix and the interface. 2. The interface between the fiber and the glass matrix show no gaps. 3. Fracture of the glass indicates characteristic fiber-matrix separation. 4. Presence of crystalline phase at high processing temperature. 5. Sapphire is compatible with bioactive glass.

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Surgical Reconstruction of the Severe Tongue Laceration with Mandibular Fracture in a Siberian Husky Dog

  • Lee, Jae-Hoon;Kim, Tae-Hoon;Yang, Wo-Jong;Kang, Eun-Hee;Chang, Hwa-Seok;Chung, Dai-Jung;Choi, Chi-Bong;Lee, Jeong-Ik;Kim, Hwi-Yool
    • Journal of Veterinary Clinics
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    • v.25 no.6
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    • pp.545-548
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    • 2008
  • A 3-year-old castrated male Siberian husky was presented for evaluation after being hit by a car. On physical examination, the dog showed open-mouth, displacement of mandible and hypersalivation with blood ting. The base of tongue was transected almost 80% on the bias from right dorsal side to the left ventral side. Radiography demonstrated separation of mandible symphysis, and fracture of right condyle and vertical ramus. After debridement of the necrotic tissue, tongue apposition with simple interrupted suture was performed. Mandibular symphysis, condyle and mandibular vertical ramus fractures were fixed using pin, cerclage wire, T-plate, and K-wires. The mouth was irrigated daily using chlorhexidine after surgery. The sutures that were loose here or untied at tongue were re-sutured under sedation. The transected tongue was healed and recovered its normal movement after 6 weeks.

Novel Phenol Resin Carbonizing Method for Carbon Interlayer Coating between Reinforcing Fiber and Matrix in Fiber Reinforced Ceramic Composite (페놀수지 탄화 코팅법을 이용한 섬유강화 복합재료 계면 형성에 관한 연구)

  • Kim, Se-Young;Woo, Sang-Kuk;Han, In-Sub
    • Journal of the Korean Ceramic Society
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    • v.46 no.3
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    • pp.301-305
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    • 2009
  • The novel carbon coating process for interlayer of fiber reinforced ceramic composites between fiber and matrix was performed by carbonizing phenolic resin solution that coated on fiber surface in $N_2$ atmosphere at $600^{\circ}C$ to improve the strength and fracture toughness of CMC(ceramic matrix composite). 160 nm carbon layer was coated on fiber surface with 5 vol% of phenolic resin solution. Since the process temperature ($600^{\circ}C$) is lower than chemical vapor deposition($900{\sim}1000^{\circ}C$), the strength and toughness could be preserved. Furthermore the coating thickness uniformity was improved to 8% of deviation along the stacking sequence. Therefore, prevention from fiber degradation during coating process and controlling coating thickness uniformity along the preform depth were achieved by coating with phenolic resin carbonizing method.

Fatigue life prediction for radial truck tires using a global-local finite element method

  • Jeong, Kyoung Moon;Beom, Hyeon Gyu;Kim, Kee-Woon;Cho, Jin-Rae
    • Interaction and multiscale mechanics
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    • v.4 no.1
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    • pp.35-47
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    • 2011
  • A global-local finite element modeling technique is employed in this paper to predict the fatigue life of radial truck tires. This paper assumes that a flaw exists inside the tire, in the local model. The local model uses an FEM fracture analysis in conjunction with a global-local technique in ABAQUS. A 3D finite element local model calculates the energy release rate at the belt edge. Using the analysis of the local model, a study of the energy release rate is performed in the crack region and used to determine the crack growth rate analysis. The result considers how different driving conditions contribute to the detrimental effects of belt separation in truck tire failure. The calculation of the total mileage on four sizes of radial truck tires has performed on the belt edge separation. The effect of the change of belt width design on the fatigue lifetime of tire belt separation is discussed.

Effect of the Compositional Modulation on the Plasticity of Amorphous Alloys: Shear Localization Viewpoint Interpretation (비정질 합금의 조성분리가 소성에 미치는 영향: 변형국부화 관점에서의 해석)

  • Lee, Mi-Rim;Park, Kyoung-Won;Sa, Hyun-Je;Lee, Jae-Chul
    • Korean Journal of Metals and Materials
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    • v.47 no.11
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    • pp.687-693
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    • 2009
  • Experiments have demonstrated that a moderate amount of Be added to $Zr_{57.5}Cu_{38.3}Al_{4.2}$ amorphous alloy enhances the plasticity of the alloy. In particular, $Zr_{54}Cu_{36}Al_{4}Be_{6}$ alloy exhibited 19% of strain to fracture along with a strength exceeding 2 GPa. Energy dispersive x-ray spectroscopy conducted on the $Zr_{54}Cu_{36}Al_{4}Be_{6}$ alloy exhibited the presence of compositional modulation, indicating that nm-scale phase separation had occurred at local regions. In this study, the role played by the nm-scale phase separation on the plasticity was investigated in terms of structural disordering, structural softening and shear localization in order to better understand the structural origin of the enhanced plasticity shown by the developed alloy.