• Journal of Veterinary Clinics
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• v.29 no.6
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• pp.502-505
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• 2012

An 8-month-old, 3.5 kg intact female Toy Poodle was presented for non-weight-bearing lameness on left hindlimb. In radiological testing, left proximal tibal type II Salter-Harris physeal fracture and fibular fracture were seen. Following open reduction, the fracture was stabilized with cross-pins, tension band wires, and a hinged transarticular external skeletal fixator (HTAESF). The range of the HTAESF was increased to $25^{\circ}$ at 7 days postsurgery and to $70^{\circ}$ at 14 days post-surgery. The HTAESF was removed 3 weeks after surgery. At 6 weeks post-surgery, the fracture was successfully healed with no complications and the patient recovered a normal gait. Seven months post-surgery, the patient had a normal gait and a normal stifle joint range of motion compared to the contralateral normal limb. This is a case in which the combined use of cross-pins, tension band wires, and HTAESF was successful for treatment of a proximal tibial physeal fracture in a dog. It is thought that these methods are beneficial for stability of fracture site and recover of joint's normal range of motion through early joint movement.

• The Journal of Advanced Prosthodontics
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• v.9 no.1
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• pp.67-73
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• 2017

PURPOSE. The aims of the study were to evaluate the fracture load of zirconia core material after dipping in coloring liquid at different time intervals and to compare the color of dipped blocks with that of prefabricated shaded blocks. MATERIALS AND METHODS. 3-unit bridge frameworks were designed digitally. Sixty frameworks were fabricated using uncolored zirconia blocks by CAD/CAM and divided into 4 groups randomly (n = 15). Group 2 (G2) was subjected to coloring liquids for 2 minutes, Group 4 (G4) for 4 minutes, and Group 6 (G6) for 6 minutes. CFS group was not subjected to any coloring procedure. After coloring, color differences between the test groups and a prefabricated shaded zirconia group (CPZ, n = 15) were evaluated by using a spectrophotometer. Fracture test was conducted immediately after shade evaluation with a Testometric test device at a cross-head speed of 1 mm/sec. Statistical analysis for evaluating color and fracture load was performed by using one way ANOVA followed by Tukey HSD test ($P{\leq}.05$). Weibull analysis was conducted for distribution of fracture load. RESULTS. There was no difference in terms of fracture load and color between CFS (1176.681 N) and G2 (985.638 N) group and between CPZ (81.340) and G2 (81.140) group, respectively. Fracture load values of G4 (779.340 N) and G6 (935.491 N) groups were statistically significantly lower than that of CFS group ($P{\leq}.005$). The color values of G4 (79.340) and G6 (79.673) groups were statistically different than that of CPZ group ($P{\leq}.005$). CONCLUSION. Prolonged immersion of zirconia in coloring liquid not only negatively affected the fracture load of the zirconia being tested in the current study but also deteriorated the desired shade of the restoration.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.38 no.1
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• pp.50-54
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• 2012

According to Luhr's classification, a fracture in the mandible with a width of less than 15-20 mm is considered to be an atrophic mandibular fracture and its incidence is very rare. Because of the reduced cross-sectional area and smaller contact area of the fractured ends as well as the poorly vascularized bony structure and delayed bone healing, an atrophic mandibular fracture is a great challenge for oral and maxillofacial surgeons. Surgeons tend to perform closed reduction, because open reduction is considered a non-life-saving surgery among elderly patients. Thus, most of them have limited experience in surgical management. According to recent reports, open reduction yields a good result, and the Association for Osteosynthesis (AO) group has recommended open reduction. This is a case report of our two experiences of open reduction and rigid fixation of atrophic mandibular fractures by the AO principle. Articles were also reviewed here.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2002.05a
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• pp.248-254
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• 2002

The most controversial topics in plasma sprayed ceramic coating system are recently mechanical properties such as bond strength, cohesive strength, toughness and so on. Determination of bond strength of coatings is one of the most important problems. In the industry, the bond strength of coating system has been estimated by Pull-off test(ASTM standard C633-79). But, without a fixed jig and specimen, it is impossible to obtain the bond strength. Therefore, it is necessary to study the critical fracture load on interface of the coating by indentation test. Because the critical fracture load plays an important role in evaluating the bond strength for plasma sprayed ceramic coating system. So, we have estimated critical fracture load in plasma sprayed ceramic coating system, and it was shown that inverse relationship between the cross-section hardness of coating and the critical fracture load(Pc). In case of the high load(1kgf, 2kgf) in $Al_{2}O_{3}+13%TiO_{2}$, it was found that the critical point(Pco), which the coating was broken on.

• Proceedings of the KSME Conference
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• 2003.04a
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• pp.13-18
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• 2003

Reduced activation ferritic steel, JLF-1 steel (Fe-9Cr-2W-V-Ta), is one of the promising candidate materials for fusion reactor applications. Fracture toughness ($J_IC$) and tensile tests were carried out at room temperature and elevated temperature ($400^{\circ}C$). Two types of CT specimen were prepared to examine the effect of rolling direction on the fracture toughness of JLF-1 steel. Four types of tensile specimen were also prepared to investigate the property by the rolling direction and welding. The Micro Vickers hardness was measured at various distances of a cross section of the TIG joints of JLF-1 steel according to the heating history of each position. Finally, the fracture surface was observed by scanning electron microscopy (SEM).

• Transactions of Materials Processing
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• v.26 no.3
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• pp.156-161
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• 2017

In this study, the reason of die fracture occurring in hot forging of an aluminum fixed scroll was studied, based on experiments and finite element predictions. The material is assumed to be rigid-viscoplastic, and the die is rigid for the finite element predictions. The stress in the tension at the wrap root is known to cause brittle fracture, and the increase in the tensile stress is owing to the unbalanced filling of material into the die cavities between both sides of the warp. Based on the empirical and numerical achievements, the effects of geometrical parameters of the material on the die fracture were examined to find practical measures for elongated die life. It has been shown from the parametric study that the material with the optimized trapezoidal cross-section, which can be easily made during cutting or the optimized cylindrical billet with its eccentric placement in the die cavity, can considerably reduce the magnitude of the tensile stress around the die corner fractured, indicating that economical manufacturing with reduced number of stages and elongated die life can be realized at once using the optimized practical initial material.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.25 no.1
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• pp.1-8
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• 2012

This study is a basic experimental research to apply FRP (Fiber Reinforced Polymer) box members to slabs and girders among various architectural structures, which receive bending stress. We prepared prefabricated FRP member and connected it to an FRP box member as a large cross section before we conducted an experiment in diverse conditions to analyze characteristics of compressive fracture behavior. In this study, we carried out a compressive fracture behavior test according to fillers on the upper part of the FRP box member, loading methods, and connective types and thereby performed a finite element analysis. The comparison of analysis results with test results revealed that rigidity was found to be slightly low, while stress was concentrated on the fracture point of the sample.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.39 no.5
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• pp.491-497
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• 2015

This paper reports an experimental study for evaluating the effect of temperature on the mode I, mode II and mixed-mode interlaminar fracture toughness of adhesive joints with a curved cross-section of filament-wound dome-separated composite pressure vessel. Mode I and mixed-mode interlaminar fracture toughness were evaluated using DCB specimens, while mode II interlaminar fracture toughness was determined using ENF specimens. $[{\pm}10^{\circ}]_6$, $[{\pm}27^{\circ}]_6$ and ($[{\pm}10^{\circ}]_3/FM73/[{\pm}27^{\circ}]_3$) winding specimens with the curved cross-section were considered. In-situ temperature environments were simulated with a range of $-30^{\circ}C-60^{\circ}C$ using an environmental chamber and furnace. Experimental results on the effect of temperature indicate that interlaminar fracture toughness tends to be high at low temperature and is degraded with increase in temperature. For specimen types, it was found that interlaminar fracture toughness of $[{\pm}10^{\circ}]_3/FM73/[{\pm}27^{\circ}]_3$ winding specimens considered as adhesive joints of dome and helical part was higher than other specimens.

• Journal of Korean Foot and Ankle Society
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• v.21 no.1
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• pp.21-26
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• 2017

Purpose: To evaluate the clinical outcome of an operation with early rehabilitation from ankle fracture in accordance with the injury type. Materials and Methods: A total of 136 patients (70 males and 66 females) who underwent surgery and early rehabilitation for ankle fractures between December 2008 and December 2013 were retrospectively reviewed. The average age was 47.9 years, with a range of 18~79 years. The mean follow-up period was 28.7 months, with a range of 24~102 months. All patients were classified in accordance with the Lauge Hansen classification and anatomic fracture site. Moreover, the presence of ligament injuries were documented. A short-leg cast was applied postoperatively for two weeks; thereafter, patients began the range-of-motion exercises after cast removal. Full weightbearing was allowed at 2 weeks postoperatively. Each patient was assessed radiologically and clinically based on the OlerudMolander score, visual analogue scale (VAS) for pain, joint stiffness, and capability of single heel raising. Results: Seventeen patients (12.5%) complained of postoperative pain (VAS score 1~3), and the incidence was higher in patients with trimalleolar fractures or associated ligament injuries. Twenty-three patients (16.9%) complained of postoperative ankle stiffness. The mean Olerud-Molander score was 75.4/80 (range, 55~80). Olerud-Molander scores were lower in patients with ligament injuries than in those with fracture alone. There was no nonunion or fracture displacement even after early weightbearing walking. Conclusion: In this retrospective series, early rehabilitation after surgical restoration of ankle mortise by anatomical reduction and stabilization was shown to be successful. Earlier motion exercise and weightbearing walking can minimize fracture complications like joint stiffness or weakness in ankle fracture.

• Restorative Dentistry and Endodontics
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• v.15 no.2
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• pp.17-33
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• 1990

The purpose of this study was to evaluate the fracture toughness of dental composite resins and to investigate the filler factor affecting the fracture behaviour on which the degree of fracture toughness depends. Six kinds of commercially available composite resin;, including two of each macrofilled, microfilled, and hybrid type were used for this study, The plane strain fracture toughness ($K_{10}$) was determined by three-point bending test using the single edge notch specimen according to the ASTM-E399. The specimens were fabricated with visible light curing or self curing of each composite resin previously inserted into a metal mold, and three-point bending test was conducted with cross-head speed of 0.1mm/min following a day's storage of the specimens in $37^{\circ}C$ distilled water. The filler volume fractions were determined by the standard ashing test according to the ISO-4049. Acoustic Emission(AE), a nondestructive testing method detecting the elastic wave released from the localized sources In material under a certain stress, was detected during three-point bending test and its analyzed data was compared with, canning electron fractographs of each specimen. The results were as follows : 1. The filler content of composite resin material was found to be highest in the hybrid type followed by the macrofilled type, and the microfilled type. 2. It was found that the value of plane strain fracture toughness of composite resin material was in the range from 0.69 MPa$\sqrt{m}$ to 1 46 MPa$\sqrt{m}$ and highest In the macrofilled type followed by the hybrid type, and the microfilled type. 3. The consequence of Acoustic Emission analysis revealed that the plane strain fracture toughness increased according as the count of Acoustic Emission events increased. 4. The higher the plane strain fracture toughness became, the higher degree of surface roughness and irregularity the fractographs demonstrated.