• Transactions of the Korean hydrogen and new energy society
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• v.29 no.6
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• pp.642-647
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• 2018

Gas compressors are mostly driven by motors. It is important to measure the power of motors to evaluate their power efficiency, because the mechanical loads of gas compressors are always varied. In order to measure the power given to the driving motors, the torque should be measured. Manufacturers of compressors usually use the torque data to calculate the compressors qualities such as power consumption, efficiencies and failures. In general, measurements for the shaft torque of the compressors have been based upon contact types, strain gauges. In the cases of larger compressors, the contact type of strain gauges have several disadvantages such as large size and high cost. In this study, a relatively inexpensive and simple torque sensing technique that is not restricted to shaft diameter is introduced using visualization technique. Particle image velocimetry (PIV) has been adopted to complete non-contact torques measurements for rotating motors. In order to compare the performance of the newly constructed torque measurement technique, torque measurement by a transducer based on MEMS technology has been performed simultaneously during experiments.

• Journal of the Korean Orthopaedic Association
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• v.55 no.1
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• pp.95-100
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• 2020

In general, most knee dislocations are reduced easily by simple traction. In rare cases, closed reduction of the knee dislocation is attempted, but ruptured ligaments or muscles are stuck in the joints and cannot be reduced. The cases of this irreducible knee dislocation have sometimes been reported. The authors encountered a case of irreducible knee posterolateral rotational dislocation that was not reduced by simple traction and report it along with a review of the literature. This case provides an opportunity for clinicians to examine the clinical considerations when experiencing an irreducible knee dislocation.

• Journal of the Korean Arthroscopy Society
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• v.9 no.2
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• pp.162-166
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• 2005

Purpose: The purpose of this study were to evaluate the results of arthroscopic PCL reconstruction and posterolateral structure reconstruction. Materials and Methods: We performed 10 cases of arthrocopic PCL and posterolateral structure reconstruction using allo-achilles tendon. The average follow-up period was 25 months. We performed KT-2000 testing and posterior drawer test for posterior instability and tibial external rotation test for posterolateral rotatory instability, and measure Tegner and Lysholm score preoperatively and compared these with the results of a final evaluation in each cases. Results: The Preoperative average KT-2000 tests was 7.1 mm, posterior drawer test was Grade III and tibial external rotation test was positive at both 30 and 90 degrees of knee flexion in all cases. Preoperative average Lysholm score was 65.9 and Tegner score was 3.1. At the final evaluation, an average KT-2000 test was 2.2 mm, posteior drawer test, Grade 0 was 2 cases, Grade 1.4 cases, Grade II, 3 cases, Grade III, 1 cases. The tibial external rotation test at both 30 and 90 degrees of knee flexion was positive in 1 cases and positive at only 90 degrees in 2 cases. Lysholm score was 87.6 and Tegner score was 5.7. The objective and subjective score of final evaluation is increased in compare with preoperative one. Conclusion: Arthrocopic PCL and posterolateral structure reconstruction using allo-achilles tendon is one of the good surgical treatment method in patients having posterior and posterolateral rotatory instability.

• Journal of the Korean Arthroscopy Society
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• v.10 no.1
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• pp.26-32
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• 2006

Purpose: We evaluated the result of the degree of reduction and anterior instability after arthroscopic treatment of tibial spine fractures. Materials and Methods: Thirty-two cases of tibial spine fractures treated with arthroscopic procedure could be evaluated and the mean follow-up period was $18\;(12{\sim}48)$ months. Evaluations included Lachman test, rotatory instability examination and side to side difference (SSD) using KT-2000 arthrometer. The degree of radiologic reduction was classified as accurate reduction, anterior elevation and reduction failure, according to which the degree of anterior instability was measured. Results: There were twenty three cases (71%) of accurate duction, eight cases (25%) of anterior elevation and one case (4%) of education failure. Eight (29%) of twenty eight cases with pull-out method showed anterior elevation. The SSDs of the accurate reduction and the anterior elevation group were 2.0 mm and 2.8 mm, respectively showing no significant difference. However, the percent age of grade 0 Lachman test and SSD less than 3 mm of the accurate reduction group were significantly higher. Conclusion: Accurate reduction is important in reducing anterior instability especially in unstable fractures. Therefore, arthroscopic pull-out method should be performed with great caution to avoid anterior elevation of the fracture fragment.

• Journal of the Korea Organic Resources Recycling Association
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• v.24 no.4
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• pp.105-112
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• 2016

The drying test was carried on the globular type cow manure pellet for use in solid fuel applications. The globular type cow manure pellet fuel was sorted according to size by rotatory sieves. The three kind of drying methods such as convection hot-air drying method, infrared ray drying method and superheated steam method were used to dry the globular type cow manure pellet. Among the three kind of drying methods, superheated steam method of dry time was the shortest. The apparent specific gravity and low calorific value of dried cow manure pelltes was about $250{\sim}350kg/m^3$ and above 3,000 kcal/kg respectively. The smaller the particle size of cow manure pellets, the less drying time was required. The time was required very less for drying smaller particle size cow manure pellet when compared to larger size. In the case of the same drying condition, it has been found that reducing the particle size of cow manure fuel pellet is an important factor for shortening the drying time of the livestock manure pellet.

• Journal of Yeungnam Medical Science
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• v.3 no.1
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• pp.41-48
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• 1986

Band 3, the predominent 95,000 dalton anion transport protein, is the major intrinsic glycoprotein of the human erythrocyte membrane. This anion carrier exists as a dimer and binds the cytoskeletons such as spectrin, ankyrin and actin. And the liposomes are vesicular structures which form spontaneouly upon hydration of phospholipids. These artificial lipid vesicles have been investigated as model of the biological membranes and as a mean of improving the delivery of nucleic acids, drugs, proteins and biological substances to specific target tissues and cells. In this study, we were purified Band 3 from the human erythrocyte membrane(ghost) was prepared by hemolysis of intact human erythrocyte with weak alkali-hypotonic solution. Band 6 was removed from ghost by extracting with solution of an ionic strength of 0.15. Band 3 and Band 4 were solubilized selectively by extracting Band 6-depleted ghosts with Triton X-100 under nondenaturing conditions. Band 3 was then purified from Triton X-100 extract treated with p-chloromercuribenzoate by sucrose density gradient ultracentrifugation. This purified Band 3 was incorporated into liposomes prepared by reverse-phase evaporation. Phosphatidyl L-serine and cholesterol(1 : 1 molar ratio) were dissolved in chloroform and then chloroform was removed by rotatory evaporation under reduced pressure. Band 3 solution without Triton X-100 was introduced into a mixture of lipids and diethylether. Diethylether was subsequently removed by evaporation. This purified Band 3 and its incorporation into liposomes were confirmed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.1
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• pp.107-114
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• 2017

A turbocharger is an engine supercharger that is driven by exhaust gas. It improves the output and fuel efficiency by increasing the charging efficiency of the mixture gas, which is achieved by changing the rotatory power of the turbine connected to the exhaust passage. It is important to control the supercharging for this purpose. A nozzle slide joint is one of the core parts. Austenitic stainless steel is currently used as the material for this part, and its excellent mechanical properties include high heat resistance and corrosion resistance. However, because of its poor machinability, there are many difficulties in producing products with complicated shapes. Machining is used in the production of nozzle slide joints for high dimensional accuracy after metal powder injection molding. As design variables in this study, we investigated the sintering temperature, product stress, deformation rate, radius of curvature of the punch, and angle of the chamfer punch, which are related to the strain and shapes. The goal is to suggest a forming process using Nitronic 60 that does not require machining to manufacture a nozzle slide joint for a turbocharger. Accordingly, we determined the best process environment using finite-element analysis, the signal-noise ratio, and the Taguchi method for experiment design. The relative density and hydrostatic pressure of the final product were in accordance with the results of the finite element analysis. Therefore, we conclude that the Taguchi method can be applied to the design process of metal powder injection molding.

• Journal of the Korean Arthroscopy Society
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• v.4 no.1
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• pp.25-31
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• 2000

Introduction : This study compared the clinical results with biceps rerouting fer the isolated posterolateral instability (PLI) and for the PLI combined with PCL injuries. Methods : 21 cases of isolated PLI (group I) and 25 cases of PLI combined with PCL rupture were included in the study. The PLI was reconstructed by modified biceps femoris rerouting technique with PCL reconstructions performed prior to the PLI correction in cases of combined injury The clinical results were reviewed and analyzed. Results : Pre-operatively positive reverse pivot shift test turned negative in 43 cases post-operatively. Increased preoperative external rotation thigh foot angle (ERTFA) showed significant differences between the two groups and all fell within normal limits post-operatively At a mean follow-up of 40.3 months, the average Lysholm knee score and. The Hospital for Special Surgery Knee Ligament Score for group I and group II revealed above 90 points without statistically significant difference between the groups. 3 cases of tenodesis failure developed and re-operation was performed. Discussion and Conclusion : The advantages of modified Clancy technique include reduced surgical damages to the iliotibial band and fixation of the biceps tendon at the isometric position. The modified biceps rerouting technique is recommended for the reconstruction of both isolated and combined PLI except in patients with severe damages at the attachment of biceps tendon.

• The Journal of Korean Academy of Prosthodontics
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• v.28 no.1
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• pp.63-94
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• 1990

The purpose of this study was to analyze the displacement and the magnitude and the mode of distribution of the stresses in the lower overdenture, the mucous membrane, the abutment tooth and the mandibular supporting bone when various denture base materials, such as acrylic resin and 0.5mm metal base, and various denture base designs were subjected to different loading schemes. For this study, the two-dimensional finite element method was used. Mandibular arch models, with only canine remaining, were fabricated. In the first denture base design, a space, approximately 1mm thick, was prepared between the denture and the dome abutment. In the second denture base design, contact between the denture and the dome abutment was eliminated except the contact of the occlusal third of the abutment. In order to represent the same physiological condition as the fixed areas of the mandible under loading schemes, the eight nodes which lie at the mandibular angle region, the coronoid process and the mandibular condyle were assumed to be fixed. Each model was loaded with a magnitude of 10 kgs on the first molar region(P1) and 7 kgs on the central incisal region (P2) in a vertical direction. Then the force of 10 kgs was applied distributively from the first premolar to the second molar of each model in a vertical direction(P3). The results were as follows. : 1. When the testing vertical loads were given to the selected points of the overdenture, the overdenture showed the rotatory phenomenon, as well as sinking and the displacements of alveolar ridge, abutment and lower border of mandible under the metal base overdenture were less than those under the acrylic resin overdenture. 2. The maximum principal stresses(the maximum tensile stresses) being considered, high tensile stresses occured at the buccal shelf area, the posterior region of the ridge crest and the anterior border region of the mandibular ramus. 3. The minimum principal stresses(the maximum compressive stresses) being considered, high compressive stresses occured at the inferior and posterior border region of the mandible, the mandibular angle and the posterior border region of the mandibular ramus. 4. The vertical load on the central incisal region(P2) produced higher equivalent stress in the mandible than that on any other region(P1, P3) because of the long lever arm distance from the fixed points to the loading point. 5. Higher equivalent stresses were distributed throughout the metal base overdenture than the resin base overdenture under the same loading condition. 6. The case of occlusal third contact of the abutment to the denture produced higher equivalent stresses in the abutment, the mandibular area around the abutment and the overdenture than the case of a 1mm space between the denture and the abutment. 7. Without regard to overdenture base materials and designs, the amounts and distribution patterns of equivalent stresses under the same loading condition were similar in the mucous membrane.

• Journal of the Korean Arthroscopy Society
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• v.13 no.1
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• pp.1-7
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• 2009

Purpose: To evaluate the 2 to 4-year follow-up results after arthroscopic anterior cruciate ligament (ACL) reconstruction using transtibial femoral tunnel at 10 or 2 O'clock position. Materials and Methods: Eighty-six ACL reconstructions could be evaluated. Evaluations included 2000 International Knee Documentation Committee (IKDC) subjective knee score, Lachman test, Pivot-shift test, KT-1000 arthrometer measurement, 2000 IKDC knee examination and second-look arthroscopy. Results: Seventy-five patients (87.2%) had over 80 in 2000 IKDC subjective knee score. Eighty-three patients (96.5%) had 1+firm end or negative Lachmann test. Seventy-eight patients (90.7%) had a negative Pivot-shift test. Eighty-three patients (96.5%) had less than 5 mm difference by KT-1000 arthrometer. Eighty patients (93.0%) were normal or nearly normal by 2000 IKDC knee examination. Second-look arthroscopy was done in fifteen cases. Nine cases showed good synovialization, four cases showed partial synovialization, two cases showed poor synovialization and graft failure was noted in one case. Conclusion: ACL reconstruction using transtibial femoral tunnel at 10 or 2 O'clock position resulted in a good outcome in terms of rotatory stability as well as antero-posterior stability.