• Journal of Korean Foot and Ankle Society
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• v.13 no.1
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• pp.80-84
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• 2009

Purpose: The purpose of this article is to assess the efficacy of a bioabsorbable polylactide (PLA) plate and screw for treating injuries of ankle fractures. Materials and Methods: 24 patients who underwent an open reduction and internal fixation operation for ankle fractures from July 2005 to March 2007 were enrolled into the study. There were 15 men and 9 women. The average age of the patients was 44 years and the average follow-up period was 16 years and two months (16.2 months). All cases were divided into low grade fracture patient (11) who belongs in type A and B of Danis-Weber classification and high grade fracture patient (13) who belongs in type C1, C2 of Danis-Weber classification, and each groups were analyzed by clinical (Meyer score) and radiological finding at the time of their last follow-up evaluation. Results: The clinical results according to Meyer scoring system, showed that all patient with low grade fracture had good to excellent result, but only 54% of patient with high grade fracture had good to excellent result. According to Cedell's radiologic finding, there were 91% cases above fair in low grade fracture. But there were 62% of patient above fair result in high grade fracture, the reduction losses were seen in 38% of patient with high grade fracture. Conclusion: Bioabsorbable PLA plate and screw is good internal fixation device which doesn't have additional operation for removal of implant because of slow absorption within the human body. It showed sufficient strength for acquisition and maintenance of reduction in low grade fracture, but need attention to use because of many cases of reduction loss in high grade fracture. So, it seems to be safe and effective when used in heeling of low grade fracture under considering about type of fracture sufficiently.

• Journal of the Korean Society of Safety
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• v.17 no.4
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• pp.45-51
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• 2002

In this study, the fracture characteristics of carbonized silicon grinding wheels were examined with tensile, compression, impact and bending test. The experiment was performed for the various grinding wheels with grain size #46, #80, and grade H, L, P, and one vitrified bond and one structure No.7. Also the centrifugal fracture rpm of carbonized silicon grinding wheels were measured and compared with the calculated values for the various wheel diameters and thicknesses. The results showed that the fracture tensile strength was $1.5~2.0Kg_f/mm^2$, and it was increased by decreasing grain size and increasing grade. The fracture compression loads were $1,600~3,000Kg_f$, and the inner stress was higher than outer's. And the absorption energy of impact test was 3.3~4.7 J, and it was increased by decreasing grain size but it was not effected by grade. The fracture bending stress was $0.1~0.2Kg_f/mm^2$, and it was increased by decreasing grain size and increasing grade. The centrifugal fracture rpm of carbonized silicon grinding wheel was about 8,500~12,000 and agreed well with the calculated value, and it was increased by decreasing diameter. However, it was almost constant for the reduction of wheel thickness.

• Journal of Welding and Joining
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• v.5 no.2
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• pp.53-59
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• 1987

The effect of applied stress, current density and heat-treatment after welding on the time to fracture, fracture behavior was investigated by the method of constant load tensile testing under catholic charging with hydrogen in E.B. welded 250,300 Grade 18% Ni Maraging steel sheet. The main results obtained are as follows: 1. All specimen showed the characteristic delayed failure and the time to fracture showed decreasing tendency with the increase in current density and applied stress. 2. Hydrogen embitterment susceptibility of notched specimen after solution-treatment and aging after welding was more increased than that of aged smooth specimen and as welded specimen. 3. Fracture surface showed a typical intergranular fracture on the border, a dimple pattern in the center of specimen and some quasi-cleavage fracture between the intergranular and the dimple.

• Journal of Acupuncture Research
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• v.26 no.1
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• pp.81-90
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• 2009

Objectives : This Study was to investigate the tendency of inpatient with Thoracolumbar Compression Fracture. Also we investigated effectiveness of Pharmacopuncture and Warming Acupuncture on Thoracolumbar Compression Fracture. Methods : We investigated 48 cases of patients with thoracolumbar compression fracture. We distributed inpatint with age, sex, number of injured vertebra, level of injured vertebra, admission duration, grade of clinical symptom, result of treatment and applied treatments. And we calculated statistically signification with this data. Results : 1. Female is prominent in distribution of sex, the average age bracket is 70's, and the largest group was accidental fall in the distribution of causes. 2. In regard to level of injury, T12 was found to be most prominent, followed in turn by L2, L1, T12. In regard to grade of clinical symptoms, Grade III was most Prominent, followed in turn by Grade IV, Grade II. In regard to grade of result of treatment, Good was most prominent. 3. There was not statistically significantly correlation about admission duration and result of treatment with number of injured vertebra, grade of clinical symptom, applied treatments. Conclusions : Most inpatients with thoracolumbar compression fracture was cured by oriental medicine treatment.

• The Journal of Advanced Prosthodontics
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• v.8 no.5
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• pp.388-395
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• 2016

PURPOSE. The purpose of this study was to evaluate the resistance to deformation under static overloading by measuring yield and fracture strength, and to analyze the failure characteristics of implant assemblies made of different titanium grades and connections. MATERIALS AND METHODS. Six groups of implant assemblies were fabricated according to ISO 14801 (n=10). These consisted of the combinations of 3 platform connections (external, internal, and morse tapered) and 2 materials (titanium grade 2 and titanium grade 4). Yield strength and fracture strength were evaluated with a computer-controlled Universal Testing Machine, and failed implant assemblies were classified and analyzed by optical microscopy. The data were analyzed using the One-way analysis of variance (ANOVA) and Student's t-test with the level of significance at P=.05. RESULTS. The group $IT4_S$ had the significantly highest values and group IT2 the lowest, for both yield strength and fracture strength. Groups $IT4_N$ and ET4 had similar yield and fracture strengths despite having different connection designs. Group MT2 and group IT2 had significant differences in yield and fracture strength although they were made by the same material as titanium grade 2. The implant system of the similar fixture-abutment interfaces and the same materials showed the similar characteristics of deformation. CONCLUSION. A longer internal connection and titanium grade 4 of the implant system is advantageous for static overloading condition. However, it is not only the connection design that affects the stability. The strength of the titanium grade as material is also important since it affects the implant stability. When using the implant system made of titanium grade 2, a larger diameter fixture should be selected in order to provide enough strength to withstand overloading.

• Journal of Acupuncture Research
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• v.25 no.3
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• pp.29-39
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• 2008

Methods : We investigated 28 cases of patients with thoracolumbar compression fracture. We divided patients into two groups : We treated one group with complex oriental medical treatment focusing on Bee Venom Acupuncture therapy, and did the other group with complex oriental medical treatment focusing on acupuncture therapy. To investigate the effectiveness of treatment applied for two groups, we used Visual Analog Scale(VAS) and Oswestry Low-back Pain Disability Index(ODI). We compared the VAS score and ODI score of two groups statistically. Results : 1. Female is prominent in distribution of sex, the average age bracket is 70's, and the largest group was Faccidental fall in the distribution of cause. 2. In regard to level of injury, T12 was found to be most prominent, followed in turn by L1, L2. In regard to grade of clinical symptoms, Grade III was most prominent, followed by Grade IV, Grade II. 3. As a result of evaluation by using VAS score and ODI score, treatment score at final was significantly different from that at the baseline in each group. 4. After treatment, Bee Venom acupuncture therapy group showed significant difference on VAS score and ODI score compared with acupuncture therapy group. Conclusions : Bee Venom acupuncture therapy can be available for relieving symptoms related with thoracolumbar compression fracture.

• Journal of the Korean Institute of Gas
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• v.19 no.6
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• pp.62-66
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• 2015

Considering for plants and structure under extreme conditions is required for the successful design, especially temperature and pressure. The ductile-brittle transition temperature (DBTT) for the materials under extreme condition needs to be considered. In this study, A-grade mild steel for the LNG carrier and offshore plant was examined by performing low-temperature Charpy V-notch (CVN) impact tests to investigate DBTT and the fracture toughness. The absorbed energy decreased gradually with the experimental temperature, which showed an upper-shelf energy region, lower shelf energy region, and transition temperature indicating DBTT. In addition, the fracture surface morphologies of the mild steels indicated ductile fractures at the upper-shelf energy level, with wide and large-sized dimples, whereas a brittle fracture surface, where was observed at the lower-shelf energy level, with both large and small cleavage facets. Based on the experimental results, ductile brittle transition temperature was estimated in about $-60^{\circ}C$.

• Nuclear Engineering and Technology
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• v.19 no.1
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• pp.1-9
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• 1987

The fracture toughness of SA 533 Grade B Class 1 steel has been studied with the Charpy impact test specimens in a range of temperature between -4$0^{\circ}C$ and 288$^{\circ}C$. The dynamic fracture toughness is measured by the instrumented precracked Charpy impact test while the static fracture toughness is by the 3-point bend test based on the unloading compliance method. The results are compared with the data obtained from the large specimens. It is known through the studies that temperature dependence of the appropriate (a low bound) value of the fracture toughness can be estimated by taking the static fracture toughness above the transition temperature and the dynamic fracture toughness below the temperature and it is also shown that the tests are satisfied with the requirements of ASTM E 813 when the side-groove is more than 14%.

• Journal of the Korean Institute of Gas
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• v.16 no.5
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• pp.35-40
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• 2012

To analyze the macroscopic fracture behavior as functions of the gas pipeline grade and the working environment, following analyses have been accomplished. Computer analysis of changes in fracture behaviors according to the working conditions of pipelines and Analysis of dynamic ductile fracture behaviors using the Battelle Two Curve Method. Recently, an economic and reliable pipe materials with improved performance has been needed for the severe pipeline working condition and new transporting materials. As the grade of pipe materials became higher, the possibility of dynamic ductile fracture could be increased. Therefore, the understanding of the technology to control and arrest the dynamic ductile fracture is important.

• Journal of the Korean Society of Physical Medicine
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• v.4 no.2
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• pp.125-131
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• 2009

Purpose：This study performed to evaluate the effect of hip fracture among persons over 50 years old, in Jeju-do, Korea, on mortality, activity of daily living(ADL). Methods：Three hundred eighteen patients over to 50 years of age who lived in Jeju-do and sustained a hip fracture from January 1st 2003 to December 31th 2004 were recruited. The information collected from the hospital records for each patient included age, sex, date of onset, and patients investigated activity grade, ADL, outdoor walking aid on 3month, 6month and 12month. Results：The incidence was 12.5/10,000 for total patients(female 17.0/10,000, male 6.3/10,000) in population over 50 years old. Patients who had lower activity grade and ADL level, showed higher mortality, and patients using outdoor walking aid showed higher mortality. Conclusion：The activity grade, ADL level, Using of outdoor walking aid affect mortality, so more programs about ADL must be developed for the life span and quality of life.