• Smart Structures and Systems
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• 제22권3호
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• pp.335-340
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• 2018

The behavior of concrete slabs in composite beam with C and L shaped angle shear connectors has been studied in this paper. These two types of angle shear connectors' instalment have been commonly utilized. In this study, the finite element (FE) analysis and soft computing method have been used both to present the shear connectors' push out tests and providing data results used later in soft computing method. The current study has been performed to present the aforementioned shear connectors' behavior based on the variable factors aiming the study of diverse factors' effects on C and L shaped angle in shear connectors. ANFIS (Adaptive Neuro Fuzzy Inference System), has been manipulated in providing the effective parameters in shear strength forecasting by providing input-data comprising: height, length, thickness of shear connectors together with concrete strength and the respective slip of shear connectors. ANFIS has been also used to identify the predominant parameters influencing the shear strength forecast in C and L formed angle shear connectors.

• 치과방사선
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• 제22권1호
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• pp.109-116
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• 1992

저자는 경북대학교 치과대학 학생중 악관절의 기능장애의 병력 및 현증이 없고 안모가 단정한 정상인 56명을 대상으로 시상정중면에서 양측의 하악우각부사이의 각도와 하악과두장축의 수평경사도를 계측하여 통계학적으로 분석한 바 다음과 같은 결과를 얻었다. 1. 시상정중면에서 하악우각부 사이의 각도는 우측이 18.50±1.48°, 좌측이 19.30±1.55°였다. 2. 하악과두장축의 수평경사도는 우측이 19.25±7.56°, 좌측이 20.27±7.05°였다. 3. 두 각도간의 관계는 우측의 경우 y=20. 31-0.0094×(r=-0 482, p<0.01), 좌측의 경우 y=20.64-0.066×(r=-0.301, p<0.05)인 것으로 나타났다(y : 하악과두장축의 수평경사도, x : 시상정중면에서 하악우각부 사이의 각도).

• 폴리머
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• 제38권4호
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• pp.464-470
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• 2014

A chemo-mechanical method was used to prepare lignin-containing cellulose nanofibrils(L-CNF) from unbleached woodpulps dispersed uniformly in an organic solvent. L-CNF/PLA composites were obtained by solvent casting method. The effects of L-CNF concentration on the composite performances were characterized by tensile test machine, contact angle machine, scanning electron microscope (SEM), and Fourier transform infrared spectroscopy (FTIR). The tensile test results indicated that the tensile strength and elongation-at-break increased by 50.6% and 31.8% compared with pure PLA. The contact angle of PLA composites decreased from $79.3^{\circ}$ to $68.9^{\circ}$. The FTIR analysis successfully showed that L-CNF had formed intermolecular hydrogen bonding with PLA matrix.

• 반도체디스플레이기술학회지
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• 제12권3호
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• pp.7-12
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• 2013

Ni-CNT(Carbon Nanotube) composite coatings is were formed by electrodeposition and their physical properties were investigated with variations of CNT content(1, 3, 6. 9 g/L) in the electrolyte solution, while the current density and electroplating time were fixed respectively at $6A/dm^2$ and 90 min.. With increasing CNT content from 1 to 9 g/L, incorporated CNTs into the composite coating were limited from 4.65 wt.% to 7.38 wt.%. Microhardness and contact angle values were increased with increasing CNT content of upto 3 g/L. With increasing the CNT content further, physical properties were degraded due to agglomeration, poor adhesion of CNTs to Ni matrix and thus rough surfaces. Optimum electroplating conditions were found to be the CNT content of 3 g/L, current density of 6 A/dm2 and electroplating time of 90 min.

• 한국기계가공학회지
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• 제2권4호
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• pp.82-87
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• 2003

Flow angle with Swirl in a horizontal circular tube and a cylindrical annuli were experimentally studied for its visualization. This present investigation deals with flow angle, flow visualization studies and vortex core by using oil smoke and a hot wire anemometer for Re = 40,000 and 50000 at X/D = 41, 59 and 71 in a horizontal circular tube. In the swirl air flow, a vortex core was formed at high swirl intensity along the test tube. The flow angle and the vortex core depended on the swirl intensity along the test tube. The results of flow angles with swirl measured by flow visualization and hot wire reasonably agree with those of Sparrow One of the primary objectives of this research was to measure the flow angle with swirl in a cylindrical annuli along the test tube for different Reynolds numbers. The Reynolds number for these measurements ranged from 60,000 to 100,000 with L/D = a to 4.

• 척추신경추나의학회지
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• 제8권1호
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• pp.15-26
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• 2013

Objectives: The purpose of this study is to find out the relationship between lumbar lordotic angle and low back pain patterns. Methods: We randomly selected the 1191 patients (595 males, 596 females) who have visited Bu-Chun Jaseng Hospital of Korean Medicine with low back pain. We have taken lumbar x-ray films and measured their lumbar lordotic angle, the angle formed between L1 superior margin and S1 superior margin. We investigated 1191 patients' low back pain patterns(date of occurence, existence of radiating pain, trend of increasing pain with lumbar extention and flexion, trend of increasing pain with standing and sitting positions) and analysed the relationship between lumbar lordotic angle and low back pain patterns. Results: 1. The lumbar lordotic angle of the acute phase patient is more straight than the chronic one. 2. The lumbar lordotic angle of the patients with radiating pain is more straight than the patients without radiating pain. 3. At acute phase, the lumbar lordotic angle of the patients with increasing pain from lumbar extention is more straight than those with increasing pain from lumbar flexion. 4. At chronic phase, the lumbar lordotic angle of the patients with increasing pain from lumbar flexion is more straight than those with increasing pain from lumbar extention. Conclusions: There was a significant correlation between lumbar lordotic angle and low back pain.

• 설비공학논문집
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• 제28권8호
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• pp.337-342
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• 2016

A marine SCR System is emerging as an alternative to comply with NOx Tier III Emission standards, a restriction on greenhouse gas from vessels implemented by the International Maritime Organization. The system is greatly affected by the uniformity of the fluid flowing into the catalyst, so the performance of the catalyst of an SCR system needs to be guaranteed. This study conducted research on a mixed evaporator of an SCR system, which is one of the factors affecting the uniformity of the fluid. When the angle of the mixed evaporator is set to $90^{\circ}$, the fluid uniformity is at its highest at 83%, under the condition that the length of the mixed evaporator be 3.5 D. When the length was 3.5 D and less, the fluid uniformity had a tendency to improve relative to the case without a bent pipe. However, a longer mixed evaporator results in a more perfect liquidity development in the pipe with a liquidity distribution similar to the case where no curved pipe is formed in front of the catalyst. A lower angle for the mixed evaporator results in a lower flow uniformity, and a longer length of the mixed evaporator results in a lower difference in the flow uniformity caused by the angle. The flow uniformity can be improved by 6% with a mixed evaporator, which confirmed that all factors applied to an SCR system have a close relationship with the efficiency.

• Journal of Advanced Marine Engineering and Technology
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• 제27권1호
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• pp.108-116
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• 2003

In this paper, the experimental results of condensation heat transfer were reported for the plate and shell heat exchangers(P&SHE) using R-l34a. An experimental refrigerant loop has been established to measure the condensation heat transfer coefficient of R-l34a in a vertical P&SHE. Two vertical counter flow channels were formed in the P&SHE by three plates of geometry with a corrugated trapezoid shape of a chevron angle of 45$^{\circ}$. Downflow of the condensing R-l34a in one channel releases heat to the cold up flow of water in the other channel. The effect of the refrigerant mass flux, average heat flux, system pressure and vapor quality of R-l34a on the measured data were explored in detail. The results indicate that at a higher vapor quality the condensation heat transfer coefficients are significantly higher. Condensation heat transfer coefficients were increased when the refrigerant mass flux was increased. A rise in the average heat flux causes an slight increase in the hr. Finally, at a higher system pressure the hr is found to be lower. Correlation is also provided for the measured heat transfer coefficients in terms of the Nusselt number.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2004년도 제22회 춘계학술대회논문집
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• pp.699-702
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• 2004

In this study, the affect of mounting axisymmetrical supersonic inlet to airfoil, which has 65 degree swept angle was numerically investigated. The parameter for this calculation are tree stream Mach number M=2.0 and 2.5, the distance between inlet spike and airfoil lower surface $L_{sw}$/$R_{cowl}$ = 1.21-1.54 and angle of attack to the airfoil 0-4. The mass capture ratio improved 3points in M=2.0 condition and 1points in M=2.5 while the mass capture ratio without airfoil surface was 57% and 71 % for each case. These are the result from increase of density and change of velocity deflection by the shock wave structure formed between inlet and airfoil surface. On the other hand, the distortion of Mach number at cowl lip plane increased by 13% in M=2.0, 3% in M=2.5 condition. The effects of the angle attack on the mass capture ratio is greater than that of the shock wave interaction between inlet and cowl, but the effects to the distortion is smaller in the range of this calculation condition. In the condition of M=2.0 with 4 degrees of angle of attack, inlet distortion of Mach number is mainly caused by the affects of the shock wave interaction between inlet and airfoil surface, while the largest angle of the velocity vector in the radial direction at cowl lip plane is caused by the affect of angle of attack. This large velocity vector made the flow inside the cowl subsonic and caused spillage, which interfere with the boundary layer of airfoil surface.

• 한국표면공학회지
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• 제46권5호
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• pp.192-196
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• 2013

Stainless steels (AISI 316L) are carburized by Inductively coupled plasma using $CH_4$ and Ar gas. The ${\gamma}_c$ phase(S-phase) is formed on the surface of stainless steel after carburizing process. The XRD peak of carburized samples is shifted to lower diffracting angle due to lattice expansion. Overall, the thickness of ${\gamma}_c$ phase showed a linear dependence with respect to increasing temperature due to the faster rate of diffusion of carbon. However, at temperatures above 500, the thickness data deviated from the linear trend. It is expected that the deviation was caused from atomic diffusion as well as other reactions that occurred at high temperatures. The interfacial contact resistance (ICR) and corrosion resistance are measured in a simulated proton exchange membrane fuel cell (PEMFC) environment. The ICR value of the carburized samples decreased from 130 $m{\Omega}cm^2$ (AISI 316L) to about 20 $m{\Omega}cm^2$. The sample carburized at 200 showed the best corrosion current density (6 ${\mu}Acm^{-2}$).