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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Transactions of the Korean Society of Mechanical Engineers B
Journal Basic Information
Journal DOI :
The Korean Society of Mechanical Engineers
Editor in Chief :
Volume & Issues
Volume 36, Issue 12 - Dec 2012
Volume 36, Issue 11 - Nov 2012
Volume 36, Issue 10 - Oct 2012
Volume 36, Issue 9 - Sep 2012
Volume 36, Issue 8 - Aug 2012
Volume 36, Issue 7 - Jul 2012
Volume 36, Issue 6 - Jun 2012
Volume 36, Issue 5 - May 2012
Volume 36, Issue 4 - Apr 2012
Volume 36, Issue 3 - Mar 2012
Volume 36, Issue 2 - Feb 2012
Volume 36, Issue 1 - Jan 2012
Selecting the target year
Characteristics of Wall Pressure over Wall with Permeable Coating
Song, Woo-Seog ; Shin, Seung-Yeol ; Lee, Seung-Bae ;
Transactions of the Korean Society of Mechanical Engineers B, volume 36, issue 11, 2012, Pages 1055~1063
DOI : 10.3795/KSME-B.2012.36.11.1055
Fluctuating wall pressures were measured using an array of 16 piezoelectric transducers beneath a turbulent boundary layer. The coating used in this experiment was an open-cell, urethane-type foam with a porosity of approximately 50 ppi. The ultimate objective of the coating is to provide a mechanical filter to reduce the wall pressure fluctuations. The boundary layer on the flat plate was measured by using a hot wire probe, and the CPM method was used to determine the skin friction coefficient. The wall pressure autospectra and streamwise wavenumber-frequency spectra were compared to assess the attenuation of the wall pressure field by the coating. The coating is shown to attenuate the convective wall pressure energy. However, the relatively rough surface of the coating in this investigation resulted in a higher mean wall shear stress, thicker boundary layer, and higher low-frequency wall pressure spectral levels compared to a smooth wall.
Extension of Low Temperature Combustion Regime by Turbocharging Using Diesel and Biodiesel Fuels
Jang, Jae-Hoon ; Oh, Seung-Mook ; Lee, Yong-Gyu ; Lee, Sun-Youp ;
Transactions of the Korean Society of Mechanical Engineers B, volume 36, issue 11, 2012, Pages 1065~1072
DOI : 10.3795/KSME-B.2012.36.11.1065
Due to its oxygen (O) content, biodiesel (BD) is advantageous in that it lowers PM emissions in CI engines. Therefore, BD is considered one of the best candidates for low temperature combustion (LTC) operation because its use can extend the regime for simultaneous reduction of PM and
. Thus, in this study, LTC operation was realized using BD and diesel with a 5~7%
fraction. Engine test results show that the use of BD increased the efficiency and reduced emissions such as PM, THC, and CO; furthermore, IMEP reduced by 10~12% owing to the lower LHV of the fuel. In particular, smoke was suppressed by up to 90% because O atoms in the BD enhanced the soot oxidation reaction. To compensate the IMEP loss, turbocharging (TC) was then tested, and the results showed that the power output increased and PM was reduced further. Moreover, TC in BD engine operation allowed a similar level of reduction in both
and PM at 11~12%
fraction, suggesting that there is a potential to widen the operating range by the combination of TC and BD.
Experimental Study on Heat Transfer Characteristics of Thermosyphon Using Nanofluids
Lee, Moo-Yeon ; Cho, Chung-Won ; Lee, Ho-Seong ; Won, Jong-Phil ; Lim, Taek-Kyu ;
Transactions of the Korean Society of Mechanical Engineers B, volume 36, issue 11, 2012, Pages 1073~1079
DOI : 10.3795/KSME-B.2012.36.11.1073
This study aims to experimentally investigate the heat transfer characteristics of a thermosyphon using nanofluids. A thermosyphon with three individual pipes, which share the internal volume of the evaporator section, was designed, and its performance was tested for various charge amounts, input powers of the evaporator section's heater, and concentrations of working fluids. The optimized charge amount of the thermosyphon using distilled water was 30%, and the thermal resistance of the thermosyphon with
nanofluid was 18.1% lower than that with Ag nanofluid. In addition, the heat transfer performance of the thermosyphon with
was optimized at an input power of 300 W at the evaporator section's heater and a charge amount of 30%.
Longitudinal Tracking of Alteration Pattern on Trabecular Bone Microarchitecture at Tibial Epiphysis Induced by Post Traumatic Osteoarthritis Over Time
Lee, Joo-Hyung ; Chun, Keyoung-Jin ; Lee, Kwon-Young ; Kim, Dae-Jun ; Kim, Han-Sung ; Lim, Do-Hyung ;
Transactions of the Korean Society of Mechanical Engineers B, volume 36, issue 11, 2012, Pages 1081~1090
DOI : 10.3795/KSME-B.2012.36.11.1081
This study aims to track the longitudinal alteration pattern on the trabecular bone microarchitecture at tibial epiphysis induced by T-OA over time using in vivo micro computed tomography (
). Ten SD rats were divided into control (n = 5) and T-OA (n = 5) groups. Anterior cruciate ligament transaction was performed for the T-OA group. The results showed that the alteration pattern on the trabecular bone microarchitecture at tibial epiphysis in the T.OA group was definitely different compared with that in the CON group from 0 to 8 weeks (approximately 4-16%, P > 0.05). In particular, a difference was observed in the bone formation and density distributions over time (from 0 or 4 to 8 weeks; approximately 5.15%, P < 0.05). An improved understanding of the alteration pattern on the trabecular bone microarchitecture at tibial epiphysis may assist in developing more targeted treatment interventions for T-OA.
Effect of Vision Coherent Sensory Cue on Roll Tilt Perception and Sensory Weighting
Lim, Hye-Rim ; Park, Su-Kyung ;
Transactions of the Korean Society of Mechanical Engineers B, volume 36, issue 11, 2012, Pages 1091~1097
DOI : 10.3795/KSME-B.2012.36.11.1091
Nowadays, some movie theaters provide additional sensory information in 3D movies to enhance visually induced motion perception. However, no studies have investigated how motion perception increases. Thus, in this study, we examined the effect of visual coherent sensory information on visually induced motion perception and quantification of sensory information. A visual stimulus rotated sinusoidally and visual coherent sensory information were applied as vibrations to a subject's foot. We measured the sway of the subject's body by using a force plate and somatosensory bar rotation that represents the subject's perception of the horizon using an encoder. By using this data, we obtained the weight of the sensory information using a Kalman filter. As a result, it was found that subjects rotated the somatosensory bar more when visual coherent vibrations were applied. The weight of vision also increased when visual coherent vibrations were applied. Thus, we can conclude that visual coherent sensory information tends to enhance visually induced motion perception and weight of vision.
Mechanical Evaluation of Posterior Dynamic Omega-wire Stabilization System
Lee, Yeon-Soo ; Song, Geun-Soo ;
Transactions of the Korean Society of Mechanical Engineers B, volume 36, issue 11, 2012, Pages 1099~1104
DOI : 10.3795/KSME-B.2012.36.11.1099
The study investigates the mechanical deformation of a newly developed screwless omega-wire dynamic system for stabilization of the spine. The omega-wire spring stabilization system was tested under tension, compression, and dynamic compressive fatigue loads. In addition, its bending deformation was compared to that of a spiral-wire spring system using FEA. A model whose hanger inter-center distance is 60 mm showed an ultimate tensile stress of 3981.7 N at a displacement of 3.61 mm and an ultimate compressive load of 535.6 N at a displacement of 2.16 mm. Under fatigue loading of 5 Hz with 10 N/1 N, it did not show any failure over 5 million cycles, and the displacement was restricted to 8-9 mm. In the FEA, the omega-wire spring system showed more flexible bending features than did the spiral-wire spring system.
Kinematic Analysis of Thoraco-Lumbar Spine in Bad Postures During Daily Life
Han, Ah-Reum ; Jeong, Ji-In ; Feng, Jun ; Kim, Yoon-Hyuk ;
Transactions of the Korean Society of Mechanical Engineers B, volume 36, issue 11, 2012, Pages 1105~1110
DOI : 10.3795/KSME-B.2012.36.11.1105
The spine is one of the most important skeletal joints, and it strongly affects the health of the musculoskeletal system. A normal spine has an S-shape, and it is very important to maintain this shape. Recently, spinal diseases such as low back pain have increased rapidly, especially among the elderly. Some of these diseases are caused by congenital spinal disorders and sporting and accident injuries as well as by bad postures. Improper spinal postures could generate excessive disc pressure, which is related to degeneration and pain. Therefore, in this study, we investigated the three-dimensional kinematic parameters of the thoraco-lumbar joint in several bad postures using a motion capture analysis technique. Different bad postures created a significant amount of flexion/extension, side bending, and axial rotation angle compared with neutral postures. Further study is necessary to investigate the disc pressure and ligament force due to the increase in joint rotation from the bad postures.
Design and Fabrication of Nasal-Implant-Shaped Scaffold and Regeneration of Nasal Cartilage Tissue for Rhinoplasty
Jung, Jin-Woo ; Jang, Jin-Ah ; Shim, Jin-Hyung ; Kim, Sung-Won ; Cho, Dong-Woo ;
Transactions of the Korean Society of Mechanical Engineers B, volume 36, issue 11, 2012, Pages 1111~1117
DOI : 10.3795/KSME-B.2012.36.11.1111
Implants for rhinoplasty should ideally be biocompatible and possess long-term stability after implantation. Silicone implants are most widely used for rhinoplasty. However, these implants suffer from problems related to high extrusion and infection rates. To minimize these complications, we propose a novel augmentation rhinoplasty technique using tissue engineering. To demonstrate its feasibility, a nasal-implant-shaped scaffold was designed using commercialized CAD software and fabricated using a Multi-head Deposition System, which is a solid freeform fabrication system that dispenses material. In vitro cell proliferation and chondrogenic differentiation tests were carried out using nasal septal chondrocytes.
Analysis of Three-Dimensional Profile of Bacterial Colony and Visualization of Fluidic Biofilm Using Fluorescent Microbeads
Kim, Kyung-Hoon ; Park, Eun-Jung ; Kim, Jung-Kyung ;
Transactions of the Korean Society of Mechanical Engineers B, volume 36, issue 11, 2012, Pages 1119~1126
DOI : 10.3795/KSME-B.2012.36.11.1119
The collective behavior of bacteria plays an important role in biofilm development. In this study, the fluidic properties of biofilms formed in Escherichia coli (E. coli) and Bacillus subtilis (B. subtilis) colonies were compared by visualizing 200-nm fluorescent beads that were initially embedded in an agar plate and distributed spontaneously on the upper surface of the growing colonies. We conducted experiments to measure the three-dimensional profile of the E. coli colony using fluorescent microbeads that did not flow in the colony. Vortical flow patterns near the edge of the B. subtilis colony were observed clearly by tracking the movement of the beads in the biofilm of the colony. The present study should be the first step toward determining the effect of fluidic biofilms on the growth and swarming dynamics of bacteria.
Heat Transfer Characteristics of 2 t/h-Class Modular Water-Tube-Type Boiler
Ahn, Joon ; Hwang, Sang-Soon ; Kim, Jong-Jin ; Kang, Sae-Byul ;
Transactions of the Korean Society of Mechanical Engineers B, volume 36, issue 11, 2012, Pages 1127~1133
DOI : 10.3795/KSME-B.2012.36.11.1127
A finned-tube-type evaporator module has been proposed for a 2 t/h-class water-tube-type industrial boiler with multiple burners. The geometry of the fins was changed at each module to equalize the evaporation. The modules were designed by considering the energy balance at each row rather than by following a conventional bulk design procedure. The designed module was built into a 2 t/h-class water-tube-type boiler, and its performance was tested. A numerical simulation was also conducted to evaluate the two- or three-dimensional effects of factors such as the inlet conditions. The numerical simulation also included the conjugate heat transfer problem to predict the fin tip temperature. The heat transfer coefficient with fins is lower than that obtained from the empirical correlation of a bare tube. The fin tip temperature from CFD is higher than that from the analytical solution.
Mask Patterning for Two-Step Metallization Processes of a Solar Cell and Its Impact on Solar Cell Efficiency
Lee, Chang-Joon ; Shin, Dong-Youn ;
Transactions of the Korean Society of Mechanical Engineers B, volume 36, issue 11, 2012, Pages 1135~1140
DOI : 10.3795/KSME-B.2012.36.11.1135
Two-step metallization processes have been proposed to achieve high-efficiency silicon solar cells, where the front-side grids are formed by silver plating after the formation of a nickel seed layer with a mask. Because the conventional mask patterning process is performed by an expensive selective printing method using either UV resist or phase change ink, however, the combination of a simple coating and laser-selective ablation processes is proposed in this study as an alternative means. As a masking material, the solar cell wafer was coated with either inexpensive wax having a low melting temperature or a fluorocarbon solution, and then, an electrode image was patterned by selectively removing the masking material using the laser. It was found that the fluorocarbon coating was not only superior to the wax coating in terms of pattern uniformity but it also increased the efficiency of the solar cell by 0.16%, as confirmed by statistical f and t tests.