• Journal of Welding and Joining
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• v.33 no.1
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• pp.41-48
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• 2015

In this study, the effect of heat input on weld metal microstructure and the effects of dissimilar weld heat affected zone in quenched and tempered ASTM A517 on the stainless steel AISI 316L is investigated through the optimization of welding parameters. For this purpose, two welding techniques are used, tungsten-conventional gas and pulsed gas with weld wire ER 309MoL with Diameter 2.4 mm. Research showed that the grain size of the heat affected zone in pulsed welding is less compared with conventional welding; weld metal structure is fully austenitic, it has a finer structure in the pulsed method. Additionally, the growth of weld metal adjacent steel A517 is different from steel 316L. Further, investigation showed that the rate of dilution is less in the pulsed method and the impact energy is increased in each three regions of the weld metal and heat affected zones in the pulsed method; the fracture in the weld metal and heat affected zone of steel 316L is quite soft and it is semi-crispy in the heat affected zone of steel A517.

• Clinics in Shoulder and Elbow
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• v.15 no.1
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• pp.25-31
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• 2012

Purpose: The clinical and radiographic outcomes of the internal fixation, which were executed on patients over the age of 65 with proximal humerus fracture by using a polyaxial angular stable locking compression plate (Non-Contact-Bridging proximal humerus plate, Zimmer, Switzerland, NCB), were evaluated. Materials and Methods: Thirty two patients over the age of 65 among the proximal humerus fracture treated with NCB plate, between August 2007 and January 2011, were chosen as the subjects. The average age of patients was 71 years, and the average postoperative follow-up period was 11.5 months. The fractures included 14 two-part and 18 three-part fractures. The clinical results were evaluated, using the visual analog scale (VAS) score and the Constant score. The radiological results were evaluated by time to union and Paavolainen method, which measures the neck shaft angle. Results: At the last follow-up examination, the mean VAS score was 3 points and the mean Constant score was 64.5 points, with bone union achieved after the average of 16.2 weeks following the surgery in all the cases. The mean neck shaft angle was 125.9 and 24 cases had good results, while 8 cases had fair results by Paavolainen method, at the last follow-up. There were 1 case of delayed union and cerclage wire failure, and 3 cases of subacromial impingement. There were no complications, such as loss of reduction, nonunion, screw loosening, or avascular necrosis of the humeral head. Conclusion: Internal fixation, using a NCB plate, was considered to be an effective surgical method in treating proximal humerus fracture in the elderly patients, on whom the fixation of the fracture and maintenance of reduction are difficult.

• Clinics in Shoulder and Elbow
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• v.14 no.1
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• pp.59-66
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• 2011

Purpose: We wanted to evaluate the clinical and radiological outcomes and the prognosis of various surgical treatments for the distal clavicle fracture with an acromioclavicular joint injury. Materials and Methods: A retrospective study of 21 patients with a minimum of 12 months follow up was done. We classified acromioclavicular (AC) injury into type I (only intra-articular fracture (IAF), 5 cases), type II (IAF with widening of the AC joint > 7 mm, 9 cases) and type III (IAF with AC joint superior subluxation > 50%, 7 cases). The distal clavicle fractures were fixed using plate (9 cases), mini screws (1 case), K wire and tension band wiring (10 cases) and transarticular pinning (1 case). Acromioclavicular or coracoacromial ligament reconstruction was not done in all the cases. Results: In 20 of 21 cases, bone union was achieved at an average of 8.4 weeks. Traumatic arthritis (5 cases), AC joint widening (4 cases) and AC joint subluxation (2 cases) were noted at the last follow up. The average UCLA score was 32.6 in the type I AC joint injuries, 34 in type II and 34.1 in type III. There was no relationship between the clinical outcomes and the preoperative AC joint injury pattern, postoperative traumatic arthritis, AC joint widening or AC joint subluxation (p>0.05). Conclusion: Satisfactory results were achieved by acute reduction and firm fixation of the distal clavicle fracture with AC joint injury. There was no relationship between the pattern of AC joint injury, the residual radiologic findings and the functional outcome.

• The Journal of Korean Academy of Prosthodontics
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• v.54 no.3
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• pp.239-245
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• 2016

Purpose: The purpose of this study was to identify clinical complications in removable partial denture (RPD) with implant-supported surveyed prostheses, and to analyze the factors associated with the complications such as location of the implant, splinting adjacent prostheses, the type of retentive clasps, Kennedy classification, and opposing dentition. Materials and Methods: A retrospective clinical study was carried out for 11 patients (7 male, 4 female), mean age of 67.5, who received RPD with Implant-supported surveyed prostheses between 2000 and 2016. The mechanical complications of 11 RPDs and 37 supporting implant prostheses and the state of natural teeth and peripheral soft tissue were examined. Then the factors associated with the complications were analyzed. Results: The average of 3.4 implant-supported prostheses were used for each RPD. Complications found during the follow-up period of an average of 42.1 months were in order of dislodgement of temporary cement-retained prostheses, opposing tooth fracture/mobility, screw fracture/loosening, clasp loosening, veneer porcelain fracture, marginal bone resorption and mobility of implant, artificial tooth fracture. Complications occurred more frequently in anterior region compared to posterior region, non-splinted prostheses compared to splinted prostheses, surveyed prostheses applied by wrought wire clasp compared to other clasps, and natural dentition compared to other removable prostheses as opposing dentition. There were no significant differences in complications according to the Kennedy classification. Conclusion: All implant-assisted RPD functioned successfully throughout the follow-up. However, further clinical studies are necessary because the clinical evidences are still not enough to guarantee the satisfactory prognosis of implant-assisted RPD for long-term result.

• Journal of Veterinary Clinics
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• v.37 no.3
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• pp.157-162
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• 2020

A 6-year-old Thoroughbred mare presented to the Korea Racing Authority Equine Hospital with dropping of the left front fetlock due to an injury sustained while racing. Radiographic examination revealed a comminuted fracture of both proximal sesamoid bones of the affected fetlock. Arthrodesis of the fetlock joint using a broad dynamic compression plate with a tension band wire was performed as a salvage procedure for the future use as a broodmare. After surgery, however, a delayed union of the bones and surgical site infection was present for a prolonged period. Staphylococcus aureus was persistently identified from the surgical site, and antimicrobial therapies were based on antibiotic sensitivity tests, including regional perfusions. The removal and replacement of surgical implants associated with seropurulent discharge was based on coordinating the development of fetlock ankylosis and infection control over 13 months. Firstly, seven screws associated with surgical drainage were replaced and bone morphogenetic protein-2 (BMP-2) and local antibiotics were placed into the surgical site to accelerate bone fusion at postoperative month 7. Further six screws, along with drainage, were removed at postoperative month 10. The plate and screws were removed from the limb due to the progression of bone fusion at postoperative month 13; BMP-2 and local antibiotics were also used. Delayed healing of arthrodesis due to surgical site infection and implant instability were treated by implant removals and antibiotic therapies, and the horse eventually showed improved weight-bearing ability of the affected limb.

• Journal of the Society of Naval Architects of Korea
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• v.51 no.6
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• pp.548-555
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• 2014

As a considerable, experimental approach, an Auto-carriage type of $CO_2$ welding machine and a MIG(Metal Inert Gas) welding robot under inert gas atmosphere were utilized in order to realize Al 5083 welding applied to hull and relevant components of green Al leisure ships. This study aims at investigating the effect of welding conditions(current, voltage, welding speed, etc) on thermal deformation that occurs as welding operation and tensile characteristics after welding, by using Al 5083, non-ferrous material, applied to manufacturing of co-environmental Al leisure ships. With respect to welding condition to minimize the thermal deformation, 150A and 16V at the wire-feed rate of 6mm/sec were acquired in the process of welding Al 5083 through an auto carriage type of $CO_2$ welding feeder. As to tensile characteristics of Al 5083 welding through a MIG welding robot, most of tensile specimens showed the fracture behavior on HAZ(Heat Affected Zone) located at the area joined with weld metal, except for some cases. Especially, for the case of the Al specimen with 5mm thickness, 284.62MPa of tensile strength and 11.41% of elongation were obtained as an actual allowable tensile stress-strain value. Mostly, after acquiring the optimum welding condition, the relevant welding data and technical requirements might be provided for actual welding operation site and welding procedure specification(WPS).

• Journal of Welding and Joining
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• v.13 no.2
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• pp.42-52
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• 1995

In the evaluation of aging degradation on the structural materials based on the fracture mechanics, the detection and size prediction of defect are very important. Aiming at nondestructive detection and size prediction ol defect with high accuracy and resolution, therefore, an lnduced Current Focusing Potential Drop(ICFPD) technique has been developed. The principle of this technique is to induce a focusing current at an exploratory region by an induction wire flowing an alternating current(AC) that is a constant ampere and frequency. Defects are assessed with the potential drops that are measured the induced current on the surface of metallic material by the potential pick-up pins. In this study, the lCFPD technique was applied for evaluating the location and size of the surface crack and blind crack made in plate specimens, and also for detecting the defects existing in valve, a field component, that were developed by SCC etc. during the service. The results of this present study show that surface crack and blind crack are able to defect with potential drop. these cracks are distinguished with the distribution of potential drop, and the crack depths can be estimated with each normalized potential drop that are parameters estimating the depth of each type crack. In the field component, the defects estimated by experiment result correspond with those in the cutting face of the measuring point within a higher sensitivity.

• Clinics in Shoulder and Elbow
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• v.1 no.1
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• pp.66-71
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• 1998

The fractures of lateral end of clavicle can be treated by conservative or operative treatment, but many authors report the higher rate of non-union with conservative treatment and that the operative treatment is more effective for the type II fractures. The authors reviewed and analysed 15 cases of lateral end fracture of clavicle which had been treated at Department of Orthopedic Surgery, Kyungpook National University Hospital from 1991 to 1996. The results were as follows; 1. Among the 15 patients, male was 6,female 9 and the average age was 46.2 years ranged from 21 to 72 years. 2. According to the classification by Rockwood, type II a was 8 cases and II b was 7 cases. 3. We treated operatively 12 cases, 9 cases with tension band wiring and 3 cases with intramedul-Iary K-wire fixation. And we treated conservatively 3 cases with Velpeau cast, but I case of nonunion was treated with tension band wiring. 4. The average follow-up was 3.2 years ranged from 2.1 to 4.7 years. 5. The functional results were evaluated with Weitzman's classification. 6. In the operatively treated cases, there were 4 cases(30.7%) in excellent, 7 cases(53.8%) in good and 2 cases(15.3%) in fair result. But, in the conservatively treated cases, there were 2 cases in good and I case in poor result, and the poor case did not united and had open reduction and internal fixation. 7. In conclusion, the operative treatment revealed good functional results in most cases (10/12) and early open reduction and internal fixation was better method than conservative treatment.

• Parasites, Hosts and Diseases
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• v.34 no.4
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• pp.267-278
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• 1996

A clinical case of CheMletietlo infestation on a dog born and raised in Korea is reported. A three-year old female Whippet was hospitalized due to a multiple fracture and displacement of the left scapula caused by a recent car accident The mite infestation was not noticed at the time of hospitalization. The dog underwent multiple operations involving internal fixation of the fractured scapula with wire and a plate, followed by extensive chemotherapy with antibiotics and prednisolone. After two months of hospitalization. a pruritic dermatitis near the left scapula developed. Multiple white dandruff-like ilakes were seen on the hair coat. especially over the dorsal spine and neck, and the dog expressed increased pruritus by frequently licking and scratching the affected areas. Local dense accumulations of skin debris that became crusty were also observed. Microscopic examination or a skin scraping revealed a heavy infestation of cheyletiella vnsfuri. as idrntified by the prrsrnce of holes of the palpi and the heart-shaped sensory organ on menu I. Immnosuppression elicited by the extensive administration of prednisolone was suspected for the initiation of the generalized mite infestation.

• Journal of the Korean Society for Nondestructive Testing
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• v.16 no.2
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• pp.86-94
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• 1996

In the life management safety evaluation of constructs base on a fracture mechanics, the size of defect is the very important parameter. ICFPD (Induced Current Focusing Potential Drop)technique has been developed for detecting and sizing of defects that exist not only on surface but also inside and interior of structural components. The principle of this technique is to induce a focusing current at an exploration region by a straight induction wire through which an alternating current (AC)flows that has constant amplitude and frequency. The potential distributed on the surface of metallic material is measured by potential pick-up pins that are settled on the probe. In this paper, this NDI technique was applied to the evaluation of surface cracks and blind cracks in plate specimens. The results of this study show that in the case of surface crack, the distribution of potential drop is varied with the inched angle of surface crack, and the potential drops in the crack region and the crack edge region are varied with the inclined angle and depth of crack. The distribution of potential drop for the blind crack is distingulished from that for the surface crack, and the potential drop in the crack region is varied with the depth of crack.