• Journal of Fisheries and Marine Sciences Education
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• v.10 no.1
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• pp.69-78
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• 1998

Thermal sprayed Cu-Ni alloy coating on the carbon steel was carried out impingement erosion-corrosion test and electrochemical corrosion test in the marine environment. The impingement erosion-corrosion behavior and electrochemical corrosion characteristics of substrate(SS400) and thermal sprayed Cu-Ni coating was investigated, and the corrosion control efficiency of Cu-Ni coating to substrate was estimated quantitatively. Main results obtained are as follows : 1) The weight loss rate of Cu-Ni coating layer by the impingement erosion-corrosion compared with substrate was smaller in high specific resistance solution than in low specific resistance solution. 2) The corrosion potential of Cu-Ni coating layer spray coating in the marine environment became more noble than that of substrate. 3) With the lapse of time, corrosion current density of Cu-Ni coating layer became stable, but that of substrate was increased. 4) As the corrosion control efficiency of Cu-Ni coating layer in the marine environment was over 90%, its anti-corrosion characteristics was excellent.

• Journal of Korean Medicine Rehabilitation
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• v.29 no.3
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• pp.173-182
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• 2019

This study is to report the effectivenes of Meridian-Test (M-test) in 2 cases on shoulder diseases. The M-test was applied to one patient diagnosed with as impingement syndrome and one patient diagnosed with tear of supraspinatus tendon. The changes in numeral rating scale and range of motion were identified to assess the progress of the treatment. After three times treatments, In example 1, the pain decreased from 6 to 0.5 and the range of flexion and abduction increased from $150^{\circ}$ to $180^{\circ}$. In example 2, the pain decreased from 6.5 to 1, and the range of shoulder flexion increased from $120^{\circ}$ to $170^{\circ}$, while the range of abduction increased from $90^{\circ}$ to $170^{\circ}$. Based on the above results, it would be effective to apply M-test to treat shoulder diseases in these two cases.

• Journal of Korean Foot and Ankle Society
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• v.11 no.2
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• pp.198-203
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• 2007

Purpose: To assess the arthroscopic findings in chronic lateral ankle instability and to evaluate the results of modified $Brostr{\ddot{o}}m$ operation and arthroscopic procedures. Materials and Methods: Twenty-nine cases with chronic lateral ankle instability were treated with modified $Brostr{\ddot{o}}m$ operation and ankle arthroscopy from May 2004 to January 2007. There were 19 male and 10 female with the mean age of 29.7 years. Mean follow up period was 15.8 months. All patients were checked preoperative stress anterior drawer and varus test with X-ray. Results: Associated injuries were 28 fat impingement projected into the joint between distal tibio-fibular space, 20 anterior impingement of soft tissue, 19 osteochondral defects and 13 loose body. Preoperative AOFAS score of pain, function and alignment were 28.9, 34.1 and 7.9 each other. They were improved into 38.7, 40.8 and 9.8 postoperatively. Conclusions: Modified $Brostr{\ddot{o}}m$ operation with ankle arthroscopy for chronic lateral ankle instability is believed to be a reliable option to obtain satisfactory results. Careful attention to the associated injuries such as distal fat impingement, anterior impingement, osteochondral defect and loose body is needed during the arthroscopy.

• Corrosion Science and Technology
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• v.12 no.5
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• pp.227-232
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• 2013

A number of components installed in the secondary system of nuclear power plants are exposed to aging mechanisms such as FAC (Flow-Accelerated Corrosion), Cavitation, Flashing, and LDIE (Liquid Droplet Impingement Erosion). Those aging mechanisms can lead to thinning of the components. In April 2013, one (1) inch small bore piping branched from the main steam line experienced leakage resulting from wall thinning in a 1,000 MWe Korean PWR nuclear power plant. During the normal operation, extracted steam from the main steam line goes to condenser through the small bore piping. The leak occurred in the downstream of an orifice. A control valve with vertical flow path was placed on in front of the orifice. This paper deals with UT (Ultrasonic Test) thickness data, SEM images, and numerical simulation results in order to analyze the extent of damage and the cause of leakage in the small bore piping. As a result, it is concluded that the main cause of the small bore pipe wall thinning is liquid droplet impingement erosion. Moreover, it is observed that the leak occurred at the reattachment point of the vortex flow in the downstream side of the orifice.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.24 no.2
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• pp.204-213
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• 2000

This study deals with jet impingement, which is extensively used in the process industries to achieve intense heating, cooling or drying rates and also widely employed as a test flow for turbulent models due to its complex flow configuration, on a flat plate by numerical methods. In this calculation, the finite volume method was employed to solve the Navier-stokes equation based on the non-orthogonal coordinate with non-staggered variable arrangement. To get a better understanding for the fluid flow and heat transfer characteristics of the turbulent jet impingements, $k-{\varepsilon}-{\overline{v^{'2}}}$ turbulent model was adapted and compared with the experimental data and the result of standard $k-{\varepsilon}$ turbulent model. Numerical calculations were carried out with various flow rates, nozzle to plate distances. In the case of the axisymmetric jet impingement on a flat plate, $k-{\varepsilon}-{\overline{v^{'2}}}$ turbulent model showed better agreement with the experimental data than the standard $k-{\varepsilon}$ turbulent model in the prediction of the mean velocity profiles, the turbulent velocity profiles. the turbulent shear stress and the heat transfer rate. The highest heat transfer rate can be obtained when the impingement occurs within the potential core..

• Clinics in Shoulder and Elbow
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• v.2 no.2
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• pp.93-98
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• 1999

Purpose: The purpose of this study was to analyze the prognostic factors for arthroscopic subacromial decompres­sion and rotator cuff debridement in impingement syndrome. Materials and Methods : Arthroscopic subacromial decompression with or without rotator cuff debridement was performed in 46 cases of 44 consecutive patients with either stage n or stage ill impingement syndrome. The patients were classified by Neer's stage and size of tear according to the criteria of Cofield. The results were assessed with UCLA rating scale. We used repeated measures ANOVA and Chi-square test to assess correlation between the results and six variables including stage, rotator cuff tear size, age at the operation, duration of symptom, throwing sports activity, and trauma history. The follow-up period averaged 53 months(range, 27 to 92 months). Results: Lower stage by Neer's stage was correlated with higher postoperative scores and with significant difference between preoperative and postoperative scores of UCLA rating scale. However, other factors did not show significant influence upon the results. The patients with complete rotator cuff who showed satisfactory results after procedures were older and had shorter symptom duration, small cuff size. Conclusions : In patients with impingement syndrome treated by arthroscopic debridement and subacromial decompression, superior results were obtained when belonged to a lower Neer stage and when the rotator cuff was only partially tom. In cases with complete rotator cuff tear, higher success rates were obtained with smaller tear sizes. Age at operation, duration of symptoms, throwing athlete, traumatic tear did not affect the results.

• Journal of Korean Orthopaedic Sports Medicine
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• v.4 no.1
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• pp.36-42
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• 2005

Purpose: To investigate the arthroscopic findings, and to evaluate the clinical outcomes of the treatment of posterior internal impingement of the shoulder in baseball players. Materials and Methods: We followed up 5 cases who were diagnosed as posterior internal impingement for the mean 15 months. All of the cases complained of the pain in the posterior shoulder at late cocking, and were positive in the relocation test added by hyper-horizontal abduction at $120^{\circ}$ abduction of the arm. We sutured posterior labral tear and SLAP lesion arthroscopically, and conducted debridement for rotator cuff. Three cases were performed of anterior capsular plication and the other two were performed of thermal capsular shrinkage. Pain, range of motion, and level of return to sports activity were assessed for the results. Results: As to the arthroscopic findings, all the five cases showed the fraying in posterosuperior labrum, and two of them was accompanied with the flap tear in posterosuperior labrum and the other one was accompanied with type 2 SLAP lesion. All the cases showed the fraying in supraspinatus, and one case showed partial tear. Meanwhile, in all the cases, the rotator cuff was impinged to the labrum at $90^{\circ}{\sim}120^{\circ}$ of abduction and external rotation. As to the postoperative results, all the cases did not complain of pain or instability while pitching, and the competition was recovered to be the mean 88%($80{\sim}100%$) of that before the injury. Conclusion: Definite diagnosis for the posterior internal impingement would be possible through arthroscopic examination. Favorable outcomes could be obtained with capsular plication or shrinkage for anterior microinstability and stretching exercise for posterior capsule tightness inducing the internal impingement.

• Journal of the Korean Society of Physical Medicine
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• v.11 no.4
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• pp.93-103
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• 2016

PURPOSE: The purpose of this study is to determine the effect of therapeutic exercise on pain, range of motion and strength, and balance ability in a patient with an anterior ankle impingement (AAI). METHODS: A-32-year-old male presented limited ankle motion and pain with forced dorsiflexion at both ankle joints. In response, a therapeutic exercise program consisted of ankle joint mobilization, strength exercises using an elastic band, and proprioceptive exercises including semi-squats and a one-legged standing exercise with open and closed eyes. The program was performed for 40 min/day, twice per week, for 8 weeks. Pain, range of motion (ROM), and muscle strength (ankle dorsiflexion, plantarflexion, inversion, and eversion), as well as a one-legged standing test of both ankles, were measured before and after 4 and 8 weeks of therapeutic exercise. RESULTS: VAS decreased in both ankles after 8 weeks of exercise, respectively, compared to baseline levels. Range of motion and strength increased in both ankles for dorsiflexion, plantarflexion, inversion, and eversion after 8 weeks of exercise compared to baseline levels. In addition, the ability to perform a one-legged standing test with eyes opened and closed improved in both legs after 8 week of exercise compared to baseline levels. CONCLUSION: These results suggest that therapeutic exercise improves pain, ROM, muscle strength, and balancing ability in patients with AAI.

• 한국전산유체공학회:학술대회논문집
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• 2005.10a
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• pp.281-285
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• 2005

Viscous solutions of supersonic jet impinging on a flat wall in a confined plenum are simulated using three-dimensional Navier-Stokes solver. A confined plenum was designed for simulating the missile launch and analyzing the behavior of the exhaust plume, which were accompanied by complex flow interactions with shock and boundary layer. Concerns of this paper are to show accurate simulation of internal flow in confined plenum and to demonstrate the jet flow structure when the jet interacts with a small opening on the side. Objectives of this numerical simulation are to understand the effect of changing the plume exit area of the plenum. Pressure and temperature rise at certain position in the plenum are traced and compared with test data.

• 한국전산유체공학회:학술대회논문집
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• 2006.10a
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• pp.20-21
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• 2006

Three kinds of jet flows encountered in the practical airframe design phase are discussed in this paper. Firstly, the side jet effect on the cavity flow over the flat plate was investigated. Secondly, the aerodynamic modeling of side jet influence on body-tail configuration was presented. Computational study of the similarity parameters was done to minimize the wind tunnel test. Lastly, supersonic jet impingement on a flat plate surrounded by solid walls was simulated numerically for both axi-symmetric and three-dimensional calculations with moving body method.