• Journal of Mechanical Science and Technology
• /
• v.17 no.9
• /
• pp.1380-1387
• /
• 2003

When a cold HPSI (High pressure Safety Injection) fluid associated with an overcooling transient, such as SGTR (Steam Generator Tube Rupture), MSLB (Main Steam Line Break) etc., enters the cold legs of a stagnated primary coolant loop, thermal stratification phenomena will arise due to incomplete mixing. If the stratified flow enters the downcomer of the reactor pressure vessel, severe thermal stresses are created in a radiation embrittled vessel wall by local overcooling. As general thermal-hydraulic system analysis codes cannot properly predict the thermal stratification phenomena, RG 1.154 requires that a detailed thermal-mixing analysis of PTS (pressurized Thermal Shock) evaluation be performed. Also. previous PTS studies have assumed that the thermal stratification phenomena generated in the stagnated loop side of a partially stagnated primary coolant loop are neutralized in the vessel downcomer by the strong flow from the unstagnated loop. On the basis of these reasons, this paper focuses on the development of a 3-dimensional thermal-mixing analysis model using PHOENICS code which can be applied to both partial and total loop stagnated cases. In addition, this paper verifies the fact that, for partial loop stagnated cases, the cold plume generated in the vessel downcomer due to the thermal stratification phenomena of the stagnated loop is almost neutralized by the strong flow of the unstagnated loop but is not fully eliminated.

• Journal of Korean Orthopaedic Sports Medicine
• /
• v.9 no.2
• /
• pp.91-97
• /
• 2010

Purpose: The purpose of this study was to evaluate the results of treatment for longitudinal meniscal tear in ACL rupture patients by clinical evaluation and $2^{nd}$ look arthroscopy. Materials and Methods: Among the patients who underwent surgery due to ACL rupture and longitudinal meniscal tear between 2002~2009, 32 patients were selected for the study. The patients were devided into three groups; group 1 had repair, group 2 had partial menisectomy due to impossible to repair, group 3 had conservative treatment due to stable meniscus. Comparative retrospective analysis was applied with KT 1000 arthrometer, Lysolm' score, Tegner activity score, IKDC subjective score, and $2^{nd}$ look arthroscopy. Results: Lysolm' score, Tegner activity score, IKDC subjective score showed no statistical difference in all three groups. KT-1000 side to side difference improved from 6.2, 6.15, 6.38 before surgery to 2.56, 2.49, 2.58 after surgery in group 1, 2, and 3, respectively. In group 1, second-look arthroscopy revealed complete healing in 12 patients, incomplete healing without any clinical symptoms in 2, and healing failure in 1. In group 2, second-look arthroscopy showed partial regeneration on margin of meniscectomy. In group 3, second-look arthroscopy revealed complete healing in 2 patients, while 4 showed incomplete healing so that have repaired. Conclusion: In the study, the outcome was better when the stable longitudinal meniscal tear on posterior horn with ACL rupture had active treatment.

• Journal of Electrical Engineering and Technology
• /
• v.6 no.3
• /
• pp.342-349
• /
• 2011

This paper presents a study on rotor asymmetry caused by broken bars and its effects on the stator current of an induction machine under an unbalanced supply voltage. The simulation of the induction machine is based on the finite element method. In the early stage of diagnosis, we show new sidebands specific to the partial rupture of the rotor bar. Experimental tests corroborate with the simulation results.

• Journal of Korean Foot and Ankle Society
• /
• v.21 no.1
• /
• pp.12-16
• /
• 2017

Purpose: Anterior drawer and varus stress radiographs are commonly to diagnose chronic lateral ankle instability. We compared the preoperative stress radiographs with the intraoperative radiographs under anesthesia to determine the accuracy and efficacy of stress radiographs in an outpatient clinical environment. Materials and Methods: Data was collected from patients who underwent a modified $Brostr{\ddot{o}}m$ operation for painful chronic unilateral lateral ankle instability between January 2014 and June 2016. Subjects were divided into three groups-complete tear, partial tear, and instability without rupture-according to the status of preoperative MRI findings of the anterior talofibular ligament. The anterior drawer and varus stress radiographs were taken preoperatively and intraoperatively under anesthesia. Results: Ninety-six patients, with a mean age of 29.63 years, were enrolled. There were 39, 46, and 11 patients in the complete tear, partial tear, and instability without rupture groups, respectively. On the anterior drawer and varus stress radiographs of the affected limb, talar anterior translation and varus tilting were significantly increased by 2.56 mm and $2.0^{\circ}$. The gaps between the unaffected limbs were also increased by 2.47 mm and $1.32^{\circ}$ after anesthesia. Although the stress radiographs were taken under anesthesia, the results were often smaller than the diagnostic value. Conclusion: Stress radiographs for painful chronic lateral ankle instability taken at the outpatient clinic might be inaccurate for diagnosis.

• Journal of the Korea Concrete Institute
• /
• v.17 no.1 s.85
• /
• pp.149-155
• /
• 2005

The purpose of this study is to investigate the flexural strengthening effects of CF(Carbon Fiber) sheet for the full-scale RC beams with multi-layer CF sheets. The partial strength reduction factors of CF sheets are suggested from the full-scale RC beams tests strengthened with multi-layer CF sheets up to six layers as well as material tests. From the material tensile tests, it was observed that the average tensile strengths of CF sheets per layer are decreased as the number of CF sheets is increased. Also the steep strength reductions of CF sheets in material test results at rupture are observed compared with the structural tests results for the full-scale RC beams strengthened with multi-layer CF sheets. Finally, the partial strength reduction factors far CF sheets up to six layers are suggested considering the effects of multi-layer and unit weight of CF sheets.

• Advances in concrete construction
• /
• v.7 no.1
• /
• pp.31-37
• /
• 2019

This paper evaluates the workability and hardened properties of self-compacting concrete (SCC) containing silica fume as the partial replacement of cement. SCC mixtures with 0, 2, 4, 6, 8 and 10% silica fume were tested for fresh and hardened properties. Slump flow with $T_{500}$ time, L-box and V-funnel tests were performed for evaluating the workability properties of SCC mixtures. Compressive strength, splitting tensile strength and modulus of rupture were performed on hardened SCC mixtures. Experiments revealed that replacement of cement by silica fume equal to and more than 4% reduced the slump flow diameter and increased the $T_{500}$ and V-funnel time linearly. Compressive strength, splitting tensile strength and modulus of rupture increased with increasing the replacement level of cement by silica fume and were found to be maximum for SCC mixture with 10% silica fume. Further, residual hardened properties of SCC mixture yielding maximum strengths (i.e., SCC with 10% silica fume) were determined experimentally after heating the concrete samples up to 200, 400, 600 and $800^{\circ}C$. Reductions in hardened properties up to $200^{\circ}C$ were found to be very close to normal vibrated concrete (NVC). For 400 and $600^{\circ}C$ reductions in hardened properties of SCC were found to be more than NVC of the same strength. Explosive spalling occurred in concrete specimens before reaching $800^{\circ}C$.

• Journal of Korean Orthopaedic Sports Medicine
• /
• v.8 no.1
• /
• pp.13-18
• /
• 2009

Purpose: To report the clinical results of patients treated for a rupture of the distal tendon of biceps brachii Materials and Methods: Between February 1987 and March 2004, we treated 16 patients with a rupture of the distal tendon of biceps brachii. 9 of 16 patients underwent surgical treatment. All cases were male, median age was 26.3(range, 16-48) years. The mean interval between injury and surgery was 4.7 days (range, 1~36 days). Operative correction was performed anatomically, using the two-incision technique(3 cases) or one-incision technique(6 cases). Clinical outcomes were evaluated one year after operation by assessing the review about the physical examination finding and radiologic findings with surgical findings, range of motion, muscle strength, subjective satisfaction, activity and return to previous occupation. and via telephone interview in cases of conservative treatment. Results: In cases of surgical treatment, 85.8%, 86.3% of flexion-extension and supination-pronation motion than healthy side were measured respectively. 75% of flexion power than healthy side was measured. Eight of nine(89%) were very satisfied. Eightl of nine returned to original job. In cases of conservative treatment, 65% of flexion power than pre-injury state was reported. Four of seven were satisfied, two were dissatisfied, one was very dissatisfied. Three of seven returned to original job. Conclusion: Early anatomic reconstruction can restore more strength and endurance for supination and flexion range and power. Conservative management may be considered for partial injuries, but operative repair must be considered in complete rupture, athletes, patient with high activity.

• Journal of the Korean institute of surface engineering
• /
• v.15 no.3
• /
• pp.138-145
• /
• 1982

The effects of the simultaneous variations of the ratio of feed gases(H2/N2 Flow ratio), feed gas flow rate (H2/N2, total-flow rate) and partial pressures of TiCl4 (PTiCl41) as well as deposition time and cobalt content of the substrate on the deposition rate of the TiN Coated Cemented Tungsten Carbide Tools were investigated. Deposition was carried out in the temperature range of 930$^{\circ}C$-1080$^{\circ}C$ and an activation energy of 46.5 Kcal/mole can be calculated. Transverse rupture strength was noticeably reduced by the TiN coating on the virgin surfa-ce of Cemented Tungsten Carbide, the extent of which was decreased according to the coa-ting thickness. Microhardness value observed on the work was in the range of 1700∼2000kg/mm, which were in well agreement with the value of bult TiN. The wear resistance of TiN layers was performed by turning test and it was observed that crater and flank resistance remarkably enhanced by TiN coating.

• Journal of Chest Surgery
• /
• v.25 no.4
• /
• pp.356-363
• /
• 1992

We have performed left lung transplantations in 15 dogs for one year and six months from June, 1990 to December, 1991 at the Repartment of Thoracic and Cardiovascular Surgery Yonsei University College of medicine, Seoul, Korea. These dogs were sacrificed at from operative day to post-operative 15 days when their general conditions were deteriorated. The gross findings of the transplanted lungs were thrombi in left atrium in three cases, partial occlusion of pulmonary artery or pulmonary veins in three cases, hemorrhage at pulmonary arterial anastomotic site in one case and bronchial anastomotic stenosis in two cases, bronchial anastomotic rupture in one case % no abnormal gross findings in four cases. The microscopic findings of the transplanted lungs were hemorrhagic infarction in one case, perivascular hemorrhage or pulmonary edema in two cases, peribronchial inflammatory cell infiltration & pneumonia in three cases, and alveolar type rejection with infiltration of type II pneumocytes and septal thickening in 3 cases. And also there were no abnormal findings including rejection or inflammatory evidences in six cases. The one among these six dogs survived to 15 days without evidence of rejection or inflammatory reaction & died due to postoperative care accident.

• Clinics in Shoulder and Elbow
• /
• v.19 no.4
• /
• pp.241-244
• /
• 2016

Calcific tendinitis of the shoulder joint is common disease causing acute pain, mainly involving the supraspinatus or infraspinatus muscle, and less frequently the teres minor or subscapularis muscle. This study reports on the satisfactory arthroscopic removal of calcium deposits as well as infraspinatus and supraspinatus muscle repair without relapse via minimal incision using suture anchors. This was a case of atypically extensive calcific tendinitis involving the infraspinatus muscle, with a bursal side partial rupture of the supraspinatus muscle in a 61-year-old female whose chief complaint was chronic pain of the right shoulder exacerbated by limited movement.