• Archives of Plastic Surgery
• /
• v.48 no.6
• /
• pp.635-640
• /
• 2021

Background Injuries to the proximal interphalangeal (PIP) joint are common and complex. However, the treatment of osteochondral defects of the head of the proximal phalanx has rarely been described. Herein, we propose a new technique for the management of unicondylar defects of the proximal phalanx that can restore joint amplitudes and provide PIP stability. Methods In this cadaveric feasibility study, unicondylar defects were generated using striking wedges and chisels. First, a transverse tunnel measuring 2 mm in diameter passing through the head of the proximal phalanx was made. A second tunnel at the base of the middle phalanx with the same diameter was then created. The hemitendon of the flexor carpi radialis graft was passed through each of these tunnels. The proximal end of the graft was interposed in the area with a loss of bone substance. The ligamentoplasty was then tensed and fixed by two anchors on the proximal phalanx. Joint amplitudes and frontal stability were measured preoperatively and postoperatively. Results There was no significant change in the joint's range of motion: preoperatively, the mean mobility arcs were -2° to 113.80°, and they were -2° to 110° after the procedure (P=0.999). There was no significant difference in joint stability (P>0.05). Conclusions Ligamentoplasty with PIP interposition appears to be a possible solution for the management of unicondylar defects of the proximal phalanx. An evaluation of clinical results is planned in order to definitively confirm the validity of this procedure.

• Journal of the Korean Geotechnical Society
• /
• v.37 no.2
• /
• pp.33-48
• /
• 2021

The rock anchorage of a suspension bridge is an outstanding anchorage type from environmental and economical perspective, although it should be applied when the bearing foundation is fresh enough to resist large cable loads. In practice, geotechnical engineers have encountered difficulties in designing the anchorage structure due to the fact that the physical behaviors of rocks against cable loads have not yet been fully proved and its design method was not established yet. In this study, model tests and numerical studies were performed to evaluate the behavior of the rock anchorage system planned under hard rock layers in domestic islands, and results suggest that the shape of asymmetric rock wedges can resist the tension loads with self weight and shear resistance. Additionally, real scale trial tests were carried out to verify the accuracy of an inclined drilling penetrating hard rock layers to install tendon to the bearing plate.

• Journal of the Korean Society of Propulsion Engineers
• /
• v.26 no.1
• /
• pp.88-97
• /
• 2022

In this study, a vitiated air heater was designed and manufactured to supply high-temperature and high-pressure air to the ground test apparatus of a direct-connected supersonic combustor, and an experiment was performed to verify the target design point. By installing wedges at the upper boundary, lower boundary and center of the nozzle exit of the vitiated air heater, it was confirmed that the Mach number satisfies the 2.0 level, and the pressure of the combustion chamber was also satisfactory compared to the design point. In the case of temperature, the measured temperature deviation was large due to the degree of exposure of the thermocouple and the slow response characteristics. After that, the isolator was connected to the rear of the vitiated air heater, and the Mach number was measured in the same method, and the Mach number at the center of the isolator eixt was slightly reduced to 1.8~1.9.

• The Journal of Korean Physical Therapy
• /
• v.34 no.2
• /
• pp.63-67
• /
• 2022

Purpose: The purpose of this study was to investigate the effect of assistance tools such as gym balls, wedges, and straps on lower extremity muscle activity and the increase in the range of motion made possible by the use of these tools. The subjects were divided into two groups: a group capable of deep-squatting (PS) and the second finding it impossible or having difficulty in performing such squats (IS). Methods: Twenty-three subjects participated in this study. Surface electromyography was used to measure the muscle activation of the rectus femoris (RF), vastus medialis (VM), and tibialis anterior (TA) muscles during deep squats, normal squats (NS), gym ball squats (GS), wedge squats (WS), and strap squats (SS). A motion analysis system was used to measure the range of motion of the knee joint during each of these exercises. Results: There was a significant difference in the RF muscle activity between the possible squat (PS) and the impossible squat (IS) groups in the GS, and there were significant differences in the RF and TA muscle activity between the groups in the WS. Both the PS group and the IS group showed a significant difference in the TA muscle activity depending on the tool used. There were also significant differences in the range of motion of the knee joints between the intervention methods using NS and those using the tools. Conclusion: In both groups, the muscle activity of the TA muscles was lower when GS, WS, and SS were performed compared to NS. In addition, compared to NS, the range of motion of the knee joint increased when the three tools were used. This study shows that the activity of the RF, VM, and TA muscles decreased and the range of motion of the knee joint increased during deep squats for both the PS and IS groups when tools were used.

• Geomechanics and Engineering
• /
• v.31 no.6
• /
• pp.599-614
• /
• 2022

One of the methods of stabilizing retaining walls, embankments, and deep excavations is the implementation of plate anchors (like the Geolock wall anchor systems). Back-to-back Mechanically Stabilized Earth (BBMSE) walls are common stabilized earth structures that can be used for bridge ramps. But so far, the analysis of the interactive behavior of two back-to-back anchored walls (BBAW) by double-plates anchors (constructed closely from each other and subjected to the limited-breadth vertical loading) including interference of their failure and sliding surfaces has not been the subject of comprehensive studies. Indeed, in this compound system, the interaction of sliding wedges of these two back-to-back walls considering the shear failure wedge of the foundation, significantly impresses on the foundation bearing capacity, adjacent walls displacements and deformations, and their stability. In this study, the effect of horizontal distance between two walls (W), breadth of loading plate (B), and position of vertical loading was investigated experimentally. In addition, the comparison of using single and equivalent double-plate anchors was evaluated. The loading plate bearing capacity and displacements, and deformations of BBAW were measured and the results are presented. To evaluate the shape, form, and how the critical failure surfaces of the soil behind the walls and beneath the foundation intersect with one another, the Particle Image Velocimetry (PIV) technique was applied. The experimental tests results showed that in this composite system (two adjacent-loaded BBAW) the effective distance of walls is about W = 2.5*H (H: height of walls) and the foundation effective breadth is about B = H, concerning foundation bearing capacity, walls horizontal displacements and their deformations. For more amounts of W and B, the foundation and walls can be designed and analyzed individually. Besides, in this compound system, the foundation bearing capacity is an exponential function of the System Geometry Variable (SGV) whereas walls displacements are a quadratic function of it. Finally, as an important achievement, doubling the plates of anchors can facilitate using concrete walls, which have limitations in tolerating curvature.

• Radiation Oncology Journal
• /
• v.3 no.2
• /
• pp.145-151
• /
• 1985

The peripheral dose distributions of wedge fields of Co-60 $\gamma-ray$ and 1 OMV x-ray were measured by the solid state detector controlled by means of semiautomatic water phentom system. The measurements were made on the principal plane parallel to the cross section of wedge filter (blade and ridge direction). For parallel motion of the detector to the beam axis the distance from the margin of radiation field at suface were 3, 5 and 10cm. For tranverse motion the depth of measurement were dm, 5, 10 and 15cm. The followings were drawn from the measurement. 1. The peripheral dose of the blade side of wedges was generally higher than that of the ridge side at symmetric point about beam axis. 2. In the superficial region phenomena of dose build-up appeared. 3. For Co-60 $\gamma-ray$ field, the peripheral dose did not monotonously decrease with the distance from the field margin but increase in some range, consequently showing a peak dose. 4. The peripheral dose did not only depend on radiation quality and field size, but also on wedge angle and wedge direction.

• Journal of the Korea Concrete Institute
• /
• v.22 no.5
• /
• pp.609-616
• /
• 2010

FRP-concrete composite deck, an innovative system, is composed of concrete in the top and FRP panel in the bottom. Bottom FRP panel can reduce self weight and improve workability. This system requires strong connection between FRP and concrete. Therefore coarse sand coating was previously applied on FRP to improve the bonding. In this study, concrete wedge method is newly introduced to enhance both vertical bond and fatigue performance. Three FRP-concrete composite deck specimens with the concrete wedges were manufactured, and static and fatigue tests were carried out. The results showed that the new FRP-concrete composite deck satisfied deflection and crack width limits set by the design codes. And the fatigue test showed that the composite deck was capable of two million load cycles under 50% of its static strength. Based on the results, it can be concluded that that this new system has outstanding mechanical and durability performance, and therefore, satisfactorily be used in designing FRP-concrete composite deck.

• Restorative Dentistry and Endodontics
• /
• v.27 no.3
• /
• pp.249-256
• /
• 2002

The use of flowable composite resins as liners in class II packable composite restoration has been suggested by some manufacturers. However, the contributions of this technique are unproven. The purpose of this study was to compare the gingival microleakage in class II packable composite restorations with or without the use of flowable composite resins as liners. Slot cavities were prepared on both proximals of 80 extracted human molars and randomly assigned to 8 groups of 20 each. The gingival margins were located at 1mm above CEJ in 80 cavities (group1-4) and 1mm below CEJ in 80 cavities (group5-8). The prepared teeth were mounted in the customized tray with adjacent teeth to simulate clinical conditions and metallic matrix band (Sectional matrix) and wooden wedges were applied. After acid etching and application of Single Bond, each group was restored with the following materials using incremental placement technique: Group 1,5 (Filtek P60), group 2, 3, 4 and group 6, 7, 8 (AeliteFlo, TetricFlow, Revolution/ Filtek P60). All specimens were thermocycled 500 times between 5$^{\circ}C$ and 55$^{\circ}C$ with 1 mimute dwell time, immersed 2% methylene blue dye for 24 hours and then rinsed with tab water. The specimens were embedded in clear resin and sectioned longitudinally through the center of restoration with a low speed diamond saw. Dye penetration at gingival margin was viewed at 20 magnification and analyzed on a scale of 0 to 4. Kruscal-Wallis One way analysis and Mann-Whitney Rank sum test were used to analyze the results. The results of this study were as follows. 1. The leakage values seen at the enamel margin were significantly lower than those seen at the dentin margin(P<0.05). 2. On the enamel margin, packable composite resins with flowable liners showed lower leakage than those without flowable liners, but there were no significant differences among the four groups(P>0.05). 3. On the dentin margin, four groups demonstrated moderate to severe leakage, and there were no significant differences in leakage values(P>0.05).

• Journal of the Korean Geotechnical Society
• /
• v.15 no.3
• /
• pp.41-70
• /
• 1999

The benefits of utilizing internal reinforced members, such as soil nails and ground anchors, in maintaining stable excavations and slopes have been known among geotechnical engineers to be very effective. Occasionally, however, both soil nails and ground anchors are simultaneously used in one excavation site. In the present study, a method of limit equilibrium stability analysis of the excavation zone reinforced with the vertically or horizontally mixed nail-anchor system is proposed to evaluate the global safety factor with respect to a sliding failure. The postulated failure wedges are determined based on the results of the $FLAC^{2D}\; 및\; FLAC^{3D}$ program analyses. This study also deals with a determination of the required thickness of the shotcrete facing. An excessive facing thickness may be required due to both the stress concentration and the relative displacement at the interface zone between the soil nailing system and the ground anchor system. A simple finite element method of analysis is presented to estimate the corresponding relative displacement at the interface zone between two different support systems. As an efficient resolution to reduce the facing thickness, the modified bearing plate system is also proposed. Finally with various analysis related to the effects of design parameters, the predicted displacements are compared with the results of the $FLAC^{2D}$ program analyses.

• Geophysics and Geophysical Exploration
• /
• v.13 no.4
• /
• pp.349-356
• /
• 2010

Analysis of high-resolution seismic profiles acquired from the southeastern continental shelf of Korea reveals that the late Quaternary transgressive deposits consist of six seismic units created in response to sea-level rise. These units with different seismic facies and geometry can be grouped into two distinct depositional wedges (paralic and marine) bounded by a ravinement surface. The paralic component underlying the ravinement surface consists of the sediment preserved from shoreface erosion and contains incised-channel fill, ancient beach-shoreface deposit and estuarine deposit. The top of paralic unit is truncated by a ravinement surface and overlain by marine component. The marine component consists of the sediment produced through shoreface erosion during landward transgression and contains mid-shelf sand sheet, mid-shelf sand ridge and inner shelf sand sheet. Such transgressive stratigraphic architecture of six sedimentary units is controlled by a function of lateral changes in the balance among rates of relative sea-level rise, sediment input and marine processes at any given time.