• Title/Summary/Keyword: Surface inclination

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A Pilot Experiments for Evaluation of Cover Soil Loss from Inclined Upland around Remediated Abandoned Mine Site - The Condition of Chemical Characteristics and Inclination - (광해복원 경사지 밭의 토양유실 평가를 위한 현장실험 - 화학적 성질과 경사도 조건에서 -)

  • Yun, Sung-Wook;Kang, Hui-Cheon;Kwon, Yo-Seb;Koh, Il-Ha;Jeong, Mun-Ho;Yu, Chan
    • Journal of The Korean Society of Agricultural Engineers
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    • v.64 no.2
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    • pp.37-45
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    • 2022
  • In-situ pilot experiment was carried out to establish a countermeasure on the soil loss from the hill side uplands that was rehabilitated by soil remediation method nearby abandoned mine sites for 2 years. It was considered that the affect of an inclination of cover surface, a stabilization treatment of cover layer by lime and steel refining slag (SRS) and a vegetation of soil surface as an effect factors in the experiment. It was constructed 4 lysimeters (plots, 22 m long, 4 m width) on the hilly side (37% inclination). One plot was control and two plots was treated by 1% lime and SRS. A remind one plot was modified a inclination to 27% to compare the affect of inclination on the amount of cover soil loss. It was attached a reservior tank and water level gauge in the end of lysimeters to measure the amount of the surface water flow and soil loss. It was also installed the automated sensors that could be collect the precipitation, soil moisture content, tension of cover layer in each plots. It was observed that the event of precipitation were caused the soil loss and it were related the physical and chemical properties of cover soil and inclination of surface layer of plots. During the experiment, it was exceeded the national regulation (50 t/ha/yr) in 37% inclination plots even though it was vegetated on the cover soil surface. However, in 27% inclination plot, it was shown that the amount of soil loss was maintained below the national regulation and, more ever, vegetation could reduce the the amount of soil loss. Therefore it was expected that such results could be applied to the future design of rehabilitation projects on the polluted farmland nearby abandoned mine sites.

Experimental study on the influence of heating surface inclination angle on heat transfer and CHF performance for pool boiling

  • Wang, Chenglong;Li, Panxiao;Zhang, Dalin;Tian, Wenxi;Qiu, Suizheng;Su, G.H.;Deng, Jian
    • Nuclear Engineering and Technology
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    • v.54 no.1
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    • pp.61-71
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    • 2022
  • Pool boiling heat transfer is widely applied in nuclear engineering fields. The influence of heating surface orientation on the pool boiling heat transfer has received extensive attention. In this study, the heating surface with different roughness was adopted to conduct pool boiling experiments at different inclination angles. Based on the boiling curves and bubble images, the effects of inclination angle on the pool boiling heat transfer and critical heat flux were analyzed. When the inclination angle was bigger than 90°, the bubble size increased with the increase of inclination angle. Both the bubble departure frequency and critical heat flux decreased as the inclination angle increased. The existing theoretical models about pool boiling heat transfer and critical heat flux were compared. From the perspective of bubble agitation model and Hot/Dry spot model, the experimental phenomena could be explained reasonably. The enlargement of bubble not only could enhance the agitation of nearby liquid but also would cause the bubble to stay longer on the heating surface. Consequently, the effect of inclination angle on the pool boiling heat transfer was not conspicuous. With the increase of inclination angle, the rewetting of heating surface became much more difficult. It has negative effect on the critical heat flux. This work provides experimental data basis for heat transfer and CHF performance of pool boiling.

Machining Time Reduction in Rough Machining of Sculptured Surface using Filleted End Mill (필렛 엔드밀을 이용한 자유곡면 황삭가공 시간단축)

  • 신동혁;김종일;김병희;주종남
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1996.11a
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    • pp.15-19
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    • 1996
  • The cusp height in ball end milling, flat end milling and filleted end milling according to various surface inclination angle was calculated. The calculation result shows that, for each kind of tools, there exists certain range of inclination angle in which cusp height characteristics favorable. From machining time calculation, filleted end mill found to be superior to flat end mill in rough machining of sculptured surface.

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Tool Deflection and Geometric Accuracy to the Change of Inclination Position Angle during Machining Sculptured Surface (곡면가공시 경사위치각 변화에 따른 공구변형과 형상정밀도)

  • 왕덕현;박희철
    • Transactions of the Korean Society of Machine Tool Engineers
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    • v.10 no.4
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    • pp.55-64
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    • 2001
  • In this study, hemisphere and cylindrical shapes were machined for different tool paths and machining conditions with ball endmill cutters. Tool deflection, cutting forces and shape accuracy were measured according to the inclination position of the sculptured surface. As the decreasing of inclination position angle, the tool deflection was increased due to the decreased cutting speed when the cutting edge is approaching toward the center. Tool deflection when upward cutting is obtained less than that of downward cutting and down-milling in upward cutting showed the least tool deflection for the sculptured surface. Roundness values were found in least roundness error when down-milling in upward cutting. It is obtained the very little difference between 90。and 45。 of inclination position angle. The best surface roughness value was obtained in upward up-milling and showed different tendency with tool deflection and cutting force. For down-milling, the cutting resistance of the side wall direction is larger than that of feed direction. Therefore, this phenomenon which is received over cutting resistance can be caused of chatter.

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Characteristics of Roughness of Inclined Surface Fabricated by Various Rapid Prototyping Processes (여러 가지 쾌속조형 방식의 경사면 거칠기 특성)

  • Kim, Gi-Dae
    • Transactions of the Korean Society of Machine Tool Engineers
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    • v.16 no.5
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    • pp.48-54
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    • 2007
  • Surface of rapid prototype has inevitably stair-stepping error, which is attributed to the continuous building process of 2 dimensional area. In this study, rounded edge model was established to estimate the roughness of inclined surface which has stair-stepping error. To investigate the roughness of rapid prototypes, specimens that have various surface inclinations were manufactured by various types of RP machines. As the surface inclination increased, the roughness of the specimens manufactured by SL, FDM, or LOM process decreased, which coincides with the simulation results. However, surface roughness of 3DP specimen was almost independent of the inclination. Furthermore, as the angle of surface increased, roughness of poly-jet specimen also increased, which is attributed to the frictional behavior between writing head and scanned area.

The Effect of Seat Surface Inclination on Respiratory Function and Speech Production in sitting (앉은 자세에서 의자 표면 경사도가 호흡기능과 구어 산출에 미치는 영향)

  • Shin, Hwa-Kyung;Kim, Hye-Su;Lee, Ok-Bun
    • The Journal of Korean Physical Therapy
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    • v.24 no.1
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    • pp.29-34
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    • 2012
  • Purpose: The purpose of this study was to evaluate the difference between respiratory function and speech production, according to the seat surface inclination while in the sitting position. Methods: Respiratory function (FVC, FEV1) and speech production (inspiratory frequency, unit reading time, paragraph reading time) were measured in 3 sitting conditions: horizontal seat surface, seat surface tilted forward 15 degrees, and seat surface tilted backward 15 degrees. Results: We found that the mean values of FVC and FEV1 were statistically significant different according to three types of sitting positions (p<0.05). The following result was observed: forward tilted sitting > horizontal sitting > backward tilted sitting. There was no significant difference in speech production between the different positions. Respiratory function and speech production had a significantly negative correlation in the forward tilted condition and the backward tilted condition. Conclusion: This finding suggests that the seat surface inclination have an effect on respiratory function. Especially, forward tilted sitting may be an effective posture that may help increases the respiratory function.

The effect of labial inclination on intrusion of the upper and lower incisors by three-dimensional finite element analysis (분절호선법으로 상하악 절치부 압하 시 순측경사도가 미치는 영향에 관한 3차원 유한요소법적 연구)

  • Kim, Dong Woo;Yang, Hoon Chul;Kim, Gi Tae;Kim, Sung Sik;Son, Woo Sung
    • The korean journal of orthodontics
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    • v.33 no.4 s.99
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    • pp.259-277
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    • 2003
  • This study was designed to investigate the position of anteroposterior center of resistance for genuine intrusion and the mode of change of the minimum distal force for simultanous intrusion and retraction of the upper and lower incisors according to the increase of labial inclination. For this purpose, we used the three-piece intrusion arch appliance and three-dimensional finite element models of upper and lower incisors. 1. Positions of the center of resistance in upper incisors according to the increase of the labial inclination were as follows; 1) In normal inclination situation, the center of resistance was located in 6m behind the distal surface of the lateral incisor bracket. 2) In $10^{\circ}$ increase of the labial inclination situation, the center of resistance was located in 9mm behind the distal surface of the lateral incisor bracket. 3) In $20^{\circ}$ increase of the labial inclination situation, the center of resistance was located in 12m behind the distal surface of the lateral incisor bracket. 4) In $30^{\circ}$ increase of the labial inclination situation, the center of resistance was located in 16m behind the distal surface of the lateral incisor bracket. 2. Positions of the center of resistance in lower incisors according to the increase of the labial inclination were as follows; 1) In normal inclination situation, the center of resistance was located in 10mm behind the distal surface of the lateral incisor bracket. 2) In $10^{\circ}$ increase of the labial inclination situation, the center of resistance was located in 13m behind the distal surface of the lateral incisor bracket. 3) In $20^{\circ}$ increase of the labial inclination situation, the center of resistance was located in 15m behind the distal surface of the lateral incisor bracket. 4) In $30^{\circ}$ increase of the labial inclination situation, the center of resistance was located in 18m behind the distal surface of the lateral incisor bracket. 3. The patterns of stress distribution were as follows; 1) There were even compressive stresses In and periodontal ligament when intrusion force was applied through determined center of resistance. 2) There were gradual increase of complexity in compressive stress distribution pattern with Increase of the labial inclination when intrusion and retraction force were applied simultaneously. 4. With increase of the labial inclination of the upper and lower incisors, the position of the center of resistance moved posteriorly. And the distal force for pure intrusion was increased until $20^{\circ}$increase of the labial inclination.

The Effects of Seat Surface Inclination on the Onset of Muscle Contraction during Sit-to-stand in Healthy Adults

  • Shin, Hwa-Kyung;Ryu, Young-Uk
    • The Journal of Korean Physical Therapy
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    • v.24 no.6
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    • pp.383-387
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    • 2012
  • Purpose: Rising from a chair is important for activities of daily living. Several factors have influence on sit-to-stand movement. We studied the effect of inclination of seat surface of on the movement of rising from a chair with electromyographic (EMG). Methods: Twelve subjects performed the sit-to-stand movement on anterior-inclined, standard, and posterior inclined chair. We measured onset time of tibialis anterior and rectus femoris with EMG on each inclination chair. Results: The onset time at the anterior-inclined chair is significantly faster than it at the standard chair (p<0.05). And the onset time at the posterior-inclined chair is significantly slower than it at the standard chair (p<0.05). Conclusion: Rising from anterior inclined chair appeared to be more effective than rising from the standard and posterior inclined chair. Therefore, this finding suggests that the selection of set surface inclination must be considered for activities of daily living during rehabilitation.

A Study on the Evaporation Characteristics of Water or Nanofluid Droplets on a Heated Surface (물과 나노유체 액적의 고온 벽면에서의 증발 특성에 관한 연구)

  • Kim, J.H.;Lee, K.J.;Jung, S.W.;Kang, B.S.
    • Journal of ILASS-Korea
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    • v.21 no.4
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    • pp.177-183
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    • 2016
  • In this study, the evaporation characteristics of water or nanofluid droplets on a heated surface was investigated by visualization of the evaporation process and evaluation of the heat transfer coefficient using the droplet temperature measured. The evaporation characteristics was compared between water and nanofluid droplets and the effects of the mass ratio of nanofluid and the inclination of heated surface were analyzed. The heat transfer rate of nanofluid droplet was higher than that of water droplet. The heat transfer coefficient was increased with the increase of the mass ratio of nanofluid. The effect of the inclination of heated surface was much higher than that of fluid type used, which indicates that the inclination of heated surface should be considered as one of influential parameters in the spray cooling process.

Experimental Study on Film Boiling Heat Transfer of Spray Cooling for Inclined heat transfer Surface (경사면에서의 분무냉각 막비등 열전달에 관한 실험적 연구)

  • Kim, Yeung-Chan
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.22 no.1
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    • pp.33-39
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    • 2010
  • The film boiling heat transfer was experimentally investigated for the water sprays impacting on an inclined hot surface. Full cone spray nozzles were employed for the spray cooling experiment, and experiments were made for different inclination angles of $\theta=0^{\circ}$, $15^{\circ}$, $30^{\circ}$ and $45^{\circ}$. The experimental results show that, in the downstream region of the inclined hot surface, increasing the inclination angle increases the local heat flux slowly because of increasing the number of rebound droplets. However, the inclination angle of heat transfer surface had no remarkable effect on the local heat flux of spray cooling under the present test conditions.