• International Journal of Air-Conditioning and Refrigeration
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• v.9 no.2
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• pp.77-84
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• 2001

Experimental and computational studies were carried out to investigate the turbulent heat transfer enhancement of the cooling system in nuclear reactor by large scale vortex generation. The large scale vortex motion was generated by rearranging the inclination angels of mixing vanes to the coordinate direction. Axial development of mean and turbulent velocities in the subchannels were measured by the 2-color LDV system. Eddy diffusivity concept based on $\kappa{-}\varepsilon$ model was employed to calculate the turbulent heat and momentum transfers in the subchannel. The turbulences generated by split mixing vanes has small length scales so that they maintain only about $10D_H$ after the spacer grid. On the other hand, the turbulences generated by the large scale vortex motions continue longer and remain up to $25D_H$ after the spacer grid.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.12 no.11
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• pp.1004-1011
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• 2000

Experimental and computational studies were carried out to confirm the turbulent enhancement of the cooling system of nuclear reactor by large scale vortex generation in nuclear fuel bundle. The large scale vortex motions were generated by rearranging the inclination angles of mixing vanes to the coordinate directions. Axial development of mean and turbulent velocities in the subchannels were measured by the 2-color LDV system. Eddy diffusivity heat flux model and $k-varepsilon$ model were employed to analyze the turbulent heat and fluid flows in the subchannel. The turbulence generated by split mixing vanes has small length scales so that they maintain only about $10 D_H$ after the spacer grid. On the other hand, the turbulences generated by the large scale vortex continue more and remain up to $25 D_H$after the spacer gird.

• The korean journal of orthodontics
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• v.15 no.2
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• pp.369-376
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• 1985

A 10 year & 11 month old girl patient who had Angle's Class III malocclusion were treated by chin cap and fixed appliances. The treatment results obtained were as to]lows: 1. The anterior crossbite was corrected. 2. The functional overbite & overjet were established. 3. The favorable molar relationships were achieved. 4. The forward growth of the mandible was restrained. 5. The axial inclination of the upper & lower incisors were changed and the upper dental arch length was increased. 6. The facial profile was improved resulting from the good upper & lower jaw relations. 7. There was no harmful changes on the teeth S the periodontal tissues after treatment. 8. The good occlusal stability was showed after 1 year of retention.

• Proceedings of the Korean Geotechical Society Conference
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• 2002.10a
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• pp.366-373
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• 2002

This paper describes the load distribution and settlement of rockbolted-drilled shafts subjected to axial and lateral loads with the view to shortening the embedded depth of the pile shaft. The emphasis was on quantifying the reinforcing effects of rockbolts placed from the shafts to surrounding weathered rocks based on small-scale model tests peformed on instrumented piles. The major influencing parameters on reinforcing drilled shaft behavior are the number, the positions on the shaft, the grade, and the inclination angle at which the rockbolts are placed. The model tests was 1/40 scaled simulations of the behavior of the drilled shafts with varying combinations of the major influencing parameters. The incremental effects of reinforcement based on the various parameters have been weighed against load transfer characteristics before and after rockbolt installations.

• Geomechanics and Engineering
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• v.38 no.4
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• pp.421-437
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• 2024

The soil nailing method entails the utilisation of nails to reinforce and stabilise a zone of soil mass. This is widely used for various applications due to its effective performance under various loading conditions. The seismic response of 6m high vertical soil-nailed cut in various site classes under dynamic excitations has been investigated in this study considering various lengths and inclinations of nails. The influence of frequency content of dynamic excitation on the response of structure has been assessed through finite element analysis using time history data of three different earthquakes. The seismic stability of the nailed cut in retaining soil in various sites under El Centro, Kobe and Trinidad earthquake ground motion is evaluated based on maximum acceleration response, maximum horizontal deformation, earth pressure distribution on the wall and maximum axial force mobilised in nails. The optimum nail inclination is identified as 15° and a minimum nail length ratio of 0.7 is essential for a stable vertical cut under dynamic excitations.

• Journal of Veterinary Clinics
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• v.33 no.6
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• pp.340-345
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• 2016

The present study determined the normal reference ranges for the femoral and tibial joint orientation angles of small-breed dogs. For this purpose, 60 each of cadaveric canine femurs and tibias from normal small-breed dogs (Maltese, Poodle, Shih Tzu, Yorkshire Terrier) were examined with radiographs and photographs. Axial and frontal radiographs and photographs of each bone were obtained, from which anteversion and inclination angles, anatomic lateral proximal and distal femoral angles (aLPFA and aLDFA), mechanical lateral proximal and distal femoral angles (mLPFA and mLDFA), and mechanical medial proximal and distal tibial angles (mMPTA and mMDTA) were measured. The 95% CI for radiographic values of all femurs and tibiae were anteversion angle, $23.4-27.4^{\circ}$; inclination angle, $128.4-130.4^{\circ}$; aLPFA, $117.8-122.1^{\circ}$; aLDFA, $93.7-95.2^{\circ}$; mLPFA $113.8-117.3^{\circ}$; mLDFA $99.2-100.5^{\circ}$; mMPTA $96.8-98.5^{\circ}$; mMDTA $89.4-90.7^{\circ}$. The Maltese had a larger anteversion angle than the Poodle and the Yorkshire Terrier and a larger mLPFA than the Poodle. In the comparison between the radiographs and the photographs, significant differences were found in the anteversion angle, mLPFA, mMPTA, and mMDTA. The established normal reference values might be useful for determining whether a valgus or varus deformity of the femur or the tibia is present and if so, the degree of angular correction needed.

• Geomechanics and Engineering
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• v.21 no.6
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• pp.571-582
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• 2020

Aiming at the mechanical and structural characteristics of the contact zone composite rock, the uniaxial compression tests and numerical studies were carried out. The interaction forms and formation mechanisms at the contact interfaces of different materials were analyzed to reveal the effect of interaction on the mechanical behavior of composite samples. The research demonstrated that there are three types of interactions between the two materials at the contact interface: constraint parallel to the interface, squeezing perpendicular to the interface, and shear stress on the interface. The interaction is mainly affected by the differences in Poisson's ratio and elastic modulus of the two materials, stronger interface adhesion, and larger interface inclination. The interaction weakens the strength and stiffness of the composite sample, and the magnitude of weakening is positively correlated with the degree of difference in the mechanical properties of the materials. The tensile-shear stress derived from the interaction results in the axial tensile fracture perpendicular to the interface and the interfacial shear facture. Tensile cracks in stronger material will propagation into the weaker material through the bonded interface. The larger inclination angle of the interface enhances the effect of composite tensile/shear failure on the overall sample.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2007.06a
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• pp.569-571
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• 2007

In this paper, hem antenna composed of rectangular hern, circular polarizer and straight-type mode convertor is designed and fabricated. The circular polarizer is designed as a dielectric type having broadband characteristic, and it is inserted into the rectangular hem with $45^{\circ}$ inclination. The straight-type mode convertor has a terrace-type structure in order to convert the TEM mode signal of coaxial cable to the TE mode of rectangular waveguide, and this structure minimizes conversion loss. Fabricated hem antenna operates at $30.085\sim30.885GHz$ and has VSWR < 1.5, Axial ratio < 1.0dB and antenna gain of $6.7\sim7.0dBi$ in the band.

• Earthquakes and Structures
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• v.14 no.3
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• pp.273-283
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• 2018

Previous experimental researches indicate that reinforced concrete beam-column joints play an important role in the mechanical properties of moment resisting frame structures, so as to require proper design. In order to get better understanding of the beam-column joint performance, a rational model needs to be developed. Based on the former considerations, two typical models for calculating the shear carrying capacity of the beam-column joint including the inelastic reinforced concrete joint model and the softened strut-and-tie model are selected to be introduced and analyzed. After examining the applicability of two typical models mentioned earlier to interior beam-column joints, several adjustments are made to get better predicting of the test results. For the softened strut-and-tie model, four adjustments including modifications of the depth of the diagonal strut, the inclination angle of diagonal compression strut, the smeared stress of mild steel bars embedded in concrete, as well as the softening coefficient are made. While two adjustments for the inelastic reinforced concrete joint model including modifications of the confinement effect due to the column axial load and the correction coefficient for high concrete are made. It has been proved by test data that predicted results by the improved softened strut-and-tie model or the modified inelastic reinforced concrete joint model are consistent with the test data and conservative. Based on the test results, it is also not difficult to find that the improved beam-column joint model can be used to predict the joint carrying capacity and cracks development with sufficient accuracy.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.25 no.2
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• pp.225-234
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• 2001

This paper represents the vector fields, three dimensional mean velocities, the turbulent intensities, the turbulent kinetic energy, and the Reynolds shear stresses in the X-Y plane of gas swirl burner with a cone type baffle plate measured by using X-probe from hot-wire anemometer system. This experiment is carried out at flow rates 350 and 450ℓ/min respectively, which are equivalent to the combustion air flow rate necessary for heat release 15,000 kcal/hr in gas furnace, in the test section of subsonic wind tunnel. The vector plot shows that the maximum axial mean velocity component exists in the narrow slits situated radially on the edge of gas swirl burner, for that reason, there is some entrainment phenomena of ambient air in the outer region of burner. Moreover, mean velocities in the initial region are largely distributed near the outer region of burner at Y/R≒0.97, but they diffuse and develop into the center flow region of burner according to the increase of axial distance. The turbulent intensities and the turbulent kinetic energy due to large inclination of mean velocity and swirl effect show that the maximum value in the initial region of burner is formed in the narrow slits situated radially on the edge of gas swirl burner and large values are mainly formed in the entire region of burner after X/R=2.4358, hence, the combustion reaction is anticipated to occur actively near this region. And the Reynolds shear stresses are also largely distributed from slite to vanes of gas swirl burner in the intial region, but their values largely disappear after X/R=3.2052.