The study compared the biomechanical performance of retrograde nail used to stabilize supracondylar fracture (three different levels) by means of finite element analysis. Three different nail lengths (200, 260, and 300 mm) of stainless steel and titanium nails were under consideration. Intact femur model was reconstructed from Digital Imaging and Communications in Medicine images of Thai cadaveric femur scanned by computed tomography spiral scanner, whereas geometry of retrograde nail was reconstructed with the data obtained from three-dimensional laser scanner. The retrograde nail was virtually attached to the femur before nodes and elements were generated for finite element model. The finite element models were analyzed in two stages, the early stage of fracture healing and the stage after fracture healing. The finding indicated that purchasing proximal locking screw in the bowing region of the femur may be at risk due to the high stresses at the implant and bone. There were no differences in stress level, elastic strain at a fracture gap, and bone stress between stainless steel and titanium implant. Since the intramedullary canal requires reaming to accommodate the retrograde nail, the length of retrograde nail should be as long as necessary. However, in case that the retrograde nail can be accommodated into the intramedullary canal without reaming, the longer retrograde nail can be used.

The geometric mismatch analysis of the retrograde nail was performed in 108 Asian cadaveric adult femora. The insertion was done virtually based on a three-dimensional geometric model derived from computed tomographic images. The investigation was performed at eight levels located at 120, 140, 160, 180, 200, 220 and 240 mm above the condylar surface. The evaluation of each level included: (1) the diameter of the intramedullary canal, (2) the percentage of area filled by the nail in the unreamed intramedullary canal, (3) the minimal reamer diameter that required enlargement of the canal to accommodate retrograde nail insertion, (4) the minimal inner cortical reaming thickness that needed to be removed, (5) the percentage of the cortical bone area that needed to be removed prior to nail insertion and (6) the deviation of the nail center from the center of the intramedullary canal. The result showed significant mismatch of the nail to most of the study specimens (94 femora, 87%), which the intramedullary canal needed extensive reaming to accommodate the nail insertion. This may lead to a high possibility of clinical complications. Redesign for proper shape and size of retrograde nail should be considered for the use in Asian population.

A bending test method was designed to investigate the failure characteristics of drilling carbon-fiber reinforced composite (CFRP) plates. The CFRP plates were fabricated and drilled to join other parts for use in aircraft structures (riveting or bolting). Each sample had two equal-sized holes at 0, θ, or -θ degrees at a fixed distance of 36 mm in the longitudinal direction. The sample dimensions were identified following a study on tensile testing singleholed samples based on the ASTM D5961 standard. The tensile test focused on three cases of laminate: [0]14, [22.5]14, and [45]14. The maximum mean forces for [0]14, [22.5]14, and [45]14 laminate configurations were 6.32, 6.59, and 7.12 kN respectively. These results were implemented into a bending test which included two configurations of laminate: [0]14 and [45]14 and two equal-sized holes with a variable distance of 0 and 9 mm in the transverse direction of the plate. The bending test configuration is presented in this paper. The results revealed different load-bearing capabilities in each of the three types of specimen configuration. Samples with two holes lying at ±9 degree affected the overall strength in the [45]14 case, and as in [0]14 there was no difference between the eccentricity and the aligned holes. In [45]14, the eccentricity decreased the maximum allowable force by 1.57 percent in the normal eccentricity case and by 15.94 percent in the alternate eccentricity case compared to the aligned case.

Solar cells have been among the first such clean energy groups that have been used, talked about, and adopted extensively in many areas. One drawback of using solar cells for energy supply not only in households but also in large cities is the space needed as well as usually requiring a flat area. For these reasons, the construction of solar farms over water is a popular concept and continues to be of interest in Thailand and the rest of the world. This research provided a case study of implementing large-scale solar cells in Southeast Asia where unexpected typhoons are common during the monsoon season. This can be addressed by binding the solar panels together to make a large platform that can remain intact in the water under various conditions. Engineers need to be confident that such binding will be safe enough to ensure the solar floating platform has no movement which may cause unexpected damage. This study developed and evaluated solar panel traction with an arrangement of 9 x 28 and 28 x 9 panels under severe wind conditions of 120 kilometers per hour (33.33 meters per second) which is equivalent to typhoons in the region. The evaluation used empirical and numerical models, and wind-tunnel testing. The resultant equation was: D (N, M) = 2075.8 N0.6532 M0.9052 and D = Kv (V) 2075.8 N0.6532 M0.9052 where N and M are the numbers of platforms in columns and rows, respectively, Kv (V) = (0.019564618+0.007704667V)/(1-0.0004656279V), and V is the wind speed (km/h). The investigation found that the predicted traction results using the derived equations was in good agreement with wind-tunnel testing for a proposed platform.