• Title/Summary/Keyword: Inclination Angle

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A Study on the Spray Cooling Characteristics on the Angle of Hot Heat Transfer Surface (고온 열전달면의 각도에 따른 분무냉각특성에 관한 연구)

  • Yoon, D.H.;Kim, K.K.;Kim, M.H.;Oh, C.;Yoon, S.H.
    • Proceedings of the Korean Society of Marine Engineers Conference
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    • 2001.11a
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    • pp.8-14
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    • 2001
  • The purpose of this study is to elucidate heat characteristics according to inclination angle of the hot flat plate at the spray cooling. As results of this experiment, the heat flux, the heat transfer coefficient and the cooling speed are increased as the liquid volume flux and subcooled temperature go up. And as the inclination angle of the heat transfer surface is increased, the cooling speed on the inclined flat plate becomes faster. It means that the cooling ability is increased because droplets were excluded by gravity.

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A Study on Dust Collection Efficiency of Axial-vane Type Cyclone for Oil Mist (오일미스트용 축상 유입식 사이클론의 집진효율에 관한 연구)

  • Yi, Chung-Seob;Shin, Hae-Joong;Lee, Chi-Woo
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.21 no.3
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    • pp.415-420
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    • 2012
  • Dust collecting performance of axial-vane type cyclone for oil mist was analyzed in this study. For predicting cut diameter size of cyclone, the number and angle of vane (${\beta}_2{^{\prime}}$) was calculated by CFD. As the result, ${\beta}_2{^{\prime}}$ was decreased as the number of vane was increased and the angle of inclination (${\beta}_2{^{\prime}}$) decreased, and it cause strong swirl flow. Therefore, it could be confirmed that as the number of vane was increased and the angle of inclination was decreased, cut diameter size was decreased. Also, by verifying the results of CFD through experiment, the cut diameter size could be 2 ${\mu}m$ at 4 $m^3/min$ of flow rate.

Analysis of Generation Efficiency for Photovoltaic system according to input radiation angle (입사각에 따른 태양광발전시스템의 발전효율 분석)

  • Kim, H.S.;Lee, K.Y.;Choi, M.H.;Cho, G.B.;Baek, H.L.;Kim, P.H.
    • Proceedings of the KIEE Conference
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    • 2003.04a
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    • pp.228-230
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    • 2003
  • This paper presents a utility interactive photovoltaic generation system with the angle of inclination and direction. This paper summarizes the results of these efforts by offering a snapshot of the configuration of photovoltaic in residential applications. The status of photovoltaic system components and interconnection and safety equipment will be summarized. This system is able to variation the angle of inclination and direction. Hence this paper discuss only results that might be useful for generation power.

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Flow Properties of Granular Sands through a Circular Orifice

  • Min, Shin-Hong;Rhee, Shang-hi;Kim, Yong-Bae
    • Archives of Pharmacal Research
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    • v.2 no.1
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    • pp.1-8
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    • 1979
  • The flow rate of various sand through circular orifice can be measured from a knowledge of a few easily measurable properties of the system. These are the orifice column and particle diameters, the angle of inclination of the orifice with the horizontal and an angle of repose of the granular sand material. Straight lines were obtained when the logarithm of the flow rate was plotted versus the logarithm of orfice diameter. No influence of excessive compaction and bed height was observed and the flow rate increased with decrease of particle diameter. The profile of flow developed the edge of the aperture in a way independent of its size. Linear relationship was observed between the angle of inclination of the orifice and the flow rate.

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A finite element based approach to observe hydrodynamic pressure in reservoir adjacent to concrete gravity dam

  • Santosh Kumar, Das;Kalyan Kumar, Mandal;Arup Guha, Niyogi
    • Ocean Systems Engineering
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    • v.12 no.4
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    • pp.385-402
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    • 2022
  • This paper deals with the study of hydrodynamic pressure in reservoir adjacent to the concrete gravity dam subjected to dynamic excitation. Widely famous finite element method is used to discretize the reservoir domain for modelling purpose. Pressure is considered as nodal variable following Eulerian approach. A suitable nonreflecting boundary condition is applied at truncated face of reservoir to make the infinite reservoir to finite one for saving the computational cost. Thorough studies have been done on generation of hydrodynamic pressure in reservoir with variation of different geometrical properties. Velocity profile and hydrodynamic pressure are observed due to harmonic excitation for variation of inclination angle of dam reservoir interface. Effect of bottom slope angle and inclined length of reservoir bottom on hydrodynamic pressure coefficient of reservoir are also observed. There is significant increase in hydrodynamic pressure and distinct changes in velocity profile of reservoir are noticeable for change in inclination angle of dam reservoir interface. Change of bottom slope and inclined length of reservoir bottom are also governing factor for variation of hydrodynamic pressure in reservoir subjected to dynamic excitation.

Difference in the Lumbosacral Region Angle according to Working Posture of patients with Low Back Pain (요통환자의 작업자세에 따른 요천추부 각도의 비교)

  • Kim, Byung-Gon;Park, Rae-Joon;Yi, Seung-Ju
    • The Journal of Korean Physical Therapy
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    • v.13 no.1
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    • pp.127-137
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    • 2001
  • Low back pain is significant problem in today's society, with lifetime incidence rate reported between 50% and 90%. Many factors associated with LBP are reported. The purpose of this studies were to be evaluated static standing posture aberrations in chronic LBP in comparison with healthy individuals. The samples including 80 subjects recruited to the following two groups:patients and control(normal) Questionnaires were completed by 40 LBP patients and 40 controls at the department of Physical Therapy, Saejong neurosurgical clinic in Taegu city from October 1, 1999 to March 30, 2000. The angle of lumbar lordosis was measured on lateral x-ray films with standing position. In LBP groups. the mean degree of lumbar lordosis, sacral inclination, and lumbosacral joint angle were 29.9 ${\pm}$ 9.3, 34.8 ${\pm}$ 8.2, and 12.7 ${\pm}$ 5.7 respectively. Control groups, the mean degree of lumbar lordosis, sacral inclination and lumbosacral joint angle were 35.3 ${\pm}$ 7.8, 34.9 ${\pm}$ 6.4 and 12.5 ${\pm}$ 4.3 respectively. there were significantly decreaseds in lumbar lordosis in Low back pain group. lumbar lordosis on the working posture had significant differences among groups(sitting position patients 31.4 ${\pm}$ 9.3, standing position patients 29.4 ${\pm}$ 9.3, sitting position control 35.0 ${\pm}$ 6.4, standing position control 35.5 ${\pm}$ 8.8, respectively) (p=0.034). sacral inclination on the working posture had differences among groups(sitting position patients 35.9 ${\pm}$ 8.7.standing position patients 33.6 ${\pm}$ 7.6, sitting position control 33.9 ${\pm}$ 5.9. standing position control 35.6 ${\pm}$ 6.8, respectively). lumbersacral joint angle on the working Posture had differences among groups(sitting position patients 12.0 ${\pm}$ 5.6, standing position patients 13.4 ${\pm}$ 5.9, sitting position control 11.2 ${\pm}$ 3.0. standing position control 13.4$^{\circ}$, respectively).

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A STUDY ON THE INTERRELATIONSHIP OF THE CONDYLAR PATH, ANTERIOR OCCLUSION AND CRANIOFACIAL MORPHOLOGY (과로와 전치부 교합과 두개안면골 형태의 상관관계에 관한 연구)

  • Kim, Sang-Chul;Nahm, Dong-Seok
    • The korean journal of orthodontics
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    • v.18 no.1 s.25
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    • pp.7-24
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    • 1988
  • The stable occlusion in function is thought as important as the esthetics in form, in order to preserve the healthy oral condition. The stable occlusion requires the harmony between the condylar guidance factors and the anterior guidance factors. The aim of this study was to evaluate the quantitative relationship between the condylar guidance factors and the anterior guidance factors, estimating statistically the measurement of the condylar paths by Pantronic and those of the anterior guidance factors, craniofacial morphology by roentgenocephalometry in 46 relatively good functional occlusion. The results of this study were as follows. 1. The measurements of the protrusive condylar path inclinations were $36.41^{\circ}$ in the right, $35.63^{\circ}$ in the left, $36.28^{\circ}$ in the mean. The measurements of Fisher's angles were $8.17^{\circ}$ in the right, $6.43^{\circ}$ in the left, $6.87^{\circ}$ in the mean. 2. The anterior facial height and the lower anterior facial height made a negative correlation with the protrusive condylar path inclination. 3. The articular eminence angle relative to the artificial articulator plane showed a positive correlation with the maximum protrusive condylar path. 4. SNA and SNB made a negative correlation with the articular eminence angle, and AAP-GoMe, AAP-DcGn, the facial height ratio had a positive correlation with the articular eminence angle. 5. The angulation of maxillary incisor lingual slope, overbite and the ratio of overbite to overiet showed a positive correlation with the articular eminence angle. 6. The angulation of maxillary incisor lingual slope , overbite, and the ratio of overbite to overjet made a positive correlation with the inclination of occlusal plane, functional occlusal plane. 7. Overbite and the ratio of overbite to overjet had a positive correlation with the angulation of maxillary incisor lingual slope. 8. The anterior guidance factors were more influenced by the mean protrusive condylar path inclination and the maximum Fisher's angle, and the regression equations of those were made.

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The Comparison on Resistance Performance and Running Attitude of Asymmetric Catamaran Changing Angle of Inclination of Tunnel Stern Exit Region (비대칭 고속 쌍동선의 선미터널 출구영역의 경사각 변화에 따른 저항성능 및 항주자세 분석)

  • Kim, Sang-Won;Seo, Kwang-Cheol;Cho, Dea-Hwan;Kim, Byung-Jae;Lee, Gyeong-Woo
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2017.11a
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    • pp.232-233
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    • 2017
  • In this research, tunnel stern was applied on the asymmetric high-speed catamaran to evaluate vessel's hydrodynamic performance by numerical method, and the tunnel stern types are distinguished by angle of inclination of tunnel exit region into 3cases ($0^{\circ}$, $3^{\circ}$ and $6^{\circ}$). Consequently, it is confirmed that the total resistances of tunnel stern which have $0^{\circ}$ of inclination are lower about 4.8-17.9% than the bare hull in the wide speed range, but those of $3^{\circ}$ and $6^{\circ}$ of inclination tunnel stern are higher than bare hull about 5-14% and 5-29%, respectively. On the other hand, trim angles of $0^{\circ}$ of inclination tunnel stern show similar trend with those of bare hull in whole ranges of FnV but those of $3^{\circ}$ and $6^{\circ}$ of inclination tunnel stern are stabilized and declined respectively after FnV=1.54. These phenomena indicated that increasing angle of inclination of tunnel exit region had negative influence on resistance performance, however, it could make vessel's operation performance better than bare hull.

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Transient features of natural convection in nanofluid (나노유체 자연대류의 과도 특성)

  • Chang, Byong-Hoon
    • Journal of Energy Engineering
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    • v.18 no.1
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    • pp.1-8
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    • 2009
  • This paper reports the experimental study of natural convection heat transfer with $Al_2O_3$-water nanofluid. Experimental apparatus was a cylindrical enclosure with adjustable fluid layer thickness, and the aspect ratio was varied between 10.9 and 30.4. Heat transfer coefficients seemed to have reached a steady value within 30 minutes as the case with pure water. But, decrease in heat transfer coefficient continued for over $1{\sim}2$ hours for inclination angle of $0^{\circ}$, and oscillation in heat transfer was observed for certain inclination angles and aspect ratios for over 10 hours. Oscillation shape and period depended on the aspect ratio and inclination angle. For example, the oscillation period for $0^{\circ}$ was more than twice that for $60^{\circ}$. The maximum Nusselt number occurred at the inclination angle of $30^{\circ}$, and the minimum occurred at $60^{\circ}$ for Rayleigh number less than 1.E5. However the present results were obtained with aggregated nanofluid and would be devoid of generalities.

Application of spherical coordinate system to facial asymmetry analysis in mandibular prognathism patients

  • Yoon, Suk-Ja;Wang, Rui-Feng;Hwang, Hyeon-Shik;Kang, Byung-Cheol;Lee, Jae-Seo;Palomo, Juan Martin
    • Imaging Science in Dentistry
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    • v.41 no.3
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    • pp.95-100
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    • 2011
  • Purpose : The purpose of this study was to compare asymmetric mandibular prognathism individuals with symmetric mandibular prognathism individuals using a new alternate spherical coordinate system. Materials and Methods : This study consisted of 47 computed tomographic images of patients with mandibular prognathism. The patients were classified into symmetric and asymmetric groups. Mandibular and ramal lines were analyzed using an alternate spherical coordinate system. The length as well as midsagittal and coronal inclination angle of the lines was obtained. The bilateral differences of the spherical coordinates of the facial lines were statistically analyzed in the groups. Results : There were significant differences between the groups in bilateral difference of the length and midsagittal inclination angle of the lines (p<0.05). The bilateral difference of the length and midsagittal inclination angle of the lines has significant correlation with chin deviation (p<0.05). Conclusion : The new alternate spherical coordinate system was able to effectively evaluate facial lines. The bilateral difference of lengths and midsagittal inclination of the facial lines might contribute to the facial asymmetry in mandibular prognathism individuals.