• Journal of Veterinary Science
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• v.21 no.5
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• pp.69.1-69.11
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• 2020

Background: An inappropriate Q angle may affect the biomechanics of the canine patellofemoral joint. Objectives: The purpose of this study was to evaluate the effects of changes in quadriceps angle (Q angle) on patellofemoral joint pressure distribution in dogs. Methods: Eight stifles were positioned at 45, 60, 75, 90, 105, and 120° of flexion in vitro, and 30% body weight was applied through the quadriceps. Patellofemoral contact pressure distribution was mapped and quantified using pressure-sensitive film. For the pressure area, mean pressure, peak pressure, medial peak pressure, and lateral peak pressure, differences between groups according to conditions for changing the Q angle were statistically compared. Results: Increases of 10° of the Q angle result in increases in the pressure area (P = 0.04), mean pressure (P = 0.003), peak pressure, and medial peak pressure (P ≤ 0.01). Increasing the Q angle by 20° increases the pressure area (P = 0.021), mean pressure (P ≤ 0.001), peak pressure (P ≤ 0.01), and medial peak pressure (P ≤ 0.01) significantly, and shows higher mean (P ≤ 0.001) and peak pressures than increasing by 10°. Decreasing the Q angle increases the mean pressure (P = 0.013), peak pressure, and lateral peak pressure (P ≤ 0.001). Conclusions: Both increases and decreases in the Q angle were associated with increased peak patellofemoral pressure, which could contribute to the overloading of the cartilage. Therefore, the abnormal Q angle should be corrected to the physiologically normal value during patellar luxation repair and overcorrection should be avoided.

• Physical Therapy Korea
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• v.13 no.4
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• pp.71-78
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• 2006

This study examined the effects of socket flexion angle in trans-tibial prosthesis on stump/socket interface pressure. Ten trans-tibial amputees voluntarily participated in this study. F-socket system was used to measure static and dynamic pressure in stump/socket interface. The pressure was measured at anterior area (proximal, middle, and distal) and posterior area (proximal, middle, and distal) in different socket flexion angles ($5^{\circ}$, $0^{\circ}$, and $10^{\circ}$). Paired t-test was used to compare pressure differences in conventional socket flexion angle of $5^{\circ}$ with pressures in socket flexion angles of $0^{\circ}$ and $10^{\circ}$ (${\alpha}$=.05). Mean pressure during standing in socket flexion angle of $10^{\circ}$ decreased significantly in anterior middle area (19.7%), posterior proximal area (10.4%), and posterior distal area (16.3%) compared with socket flexion angle of $5^{\circ}$. Mean pressure during stance phase in socket flexion angle of $0^{\circ}$ increased significantly in anterior proximal area (19.3%) and decreased significantly in anterior distal area (19.7%) compared with socket flexion angle of $5^{\circ}$. Mean pressure during stance phase in socket flexion angle of $10^{\circ}$ decreased significantly in anterior proximal area (19.6%) and increased significantly in anterior distal area (8.2%) compared with socket flexion angle of $5^{\circ}$. Peak pressure during gait in socket flexion angle of $0^{\circ}$ increased significantly in anterior proximal area (23.0%) compared with socket flexion angle of $5^{\circ}$ and peak pressure during gait in socket flexion angle of $10^{\circ}$ decreased significantly in anterior proximal area (22.7%) compared with socket flexion angle of $5^{\circ}$. Mean pressure over 80% of peak pressure ($MP_{80+}$) during gait in socket flexion angle of $0^{\circ}$ increased significantly in anterior proximal area (23.9%) and decreased significantly in anterior distal area (22.5%) compared with socket flexion angle of $5^{\circ}$. $MP_{80+}$ during gait in socket flexion angle of $10^{\circ}$ decreased significantly in anterior distal area (34.1%) compared with socket flexion angle of $5^{\circ}$. Asymmetrical pressure change patterns in socket flexion angle of $0^{\circ}$ and $10^{\circ}$ were revealed in anterior proximal and distal region compared with socket flexion angle of $5^{\circ}$. To provide comfortable and safe socket for trans-tibial amputee, socket flexion angle must be considered.

• Journal of ILASS-Korea
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• v.16 no.4
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• pp.201-209
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• 2011

Optimum engine performance is obtained when the spray characteristics is well matched to the geometry of a combustion chamber. Among many parameters governing the combustion performance in internal combustion engine, fuel supply characteristics and atomization are important performance factors. Therefore, spray characteristics of high pressure multi-hole injector has been studied experimentally. An experimental test system has been made to operate high pressure injection system and to visualize spray behavior. Spray visualization has been performed to analyze spray formation, spray cone angle, bent angle and penetration length. Spray interaction with piston has been analyzed with various injector installation angle, injection pressure and ambient pressure. Test results show that penetration length is greatly influenced by the injection pressure. Penetration length is decreased as ambient pressure increased. Spray cone angle is increased as injection pressure and ambient pressure increased. However, bent angle is not influenced by the change of injection pressure and ambient pressure. Spray cone angle distribution map is plotted using the experimental data. Fuel movement around the spark-plug has been enforced as increasing injector installation angle.

• Transactions of the Korean Society of Automotive Engineers
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• v.4 no.2
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• pp.137-146
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• 1996

Behaviour of ultra-high pressure diesel spray and its structure in a constant-volume pressure chamber were studied with injection pressure ranging from 35 to 110MPa. Sprays were observed by using the back illumination scattering method and righ angle scattering method. The spray process mechanism were investigated with both photographs. As a result, the spray angle and air entrainment angle was larger as injection pressure and back pressure increase. It becomes clear that mean air-fuel ratio is increased by increasing the injection pressure.

• Journal of the Korean Society of Physical Medicine
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• v.16 no.3
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• pp.115-121
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• 2021

PURPOSE: This study analyzed the correlation between the plantar pressure and body alignment according to the dominant hand of elementary school baseball players. METHODS: The subjects consisted of 32 elementary school baseball players. The 32 players were classified in the right-hand dominant group (Rt. Group, n = 22) and left-hand dominant group (Lt. group, n = 10). The plantar pressure was measured using a pedoscan to determine the maximum pressure and pressure distribution. The body alignment was measured using a fometric 4D to measure the trunk imbalance angle (TI), pelvic tilt angle (PTi), pelvic torsion angle (PTo), pelvis rotation angle (PR), kyphotic angle (Ky), lordotic angle (Lo), and trunk torsion angle (TT). RESULTS: Participants showed correlations in the Rt. group, according to the left maximum pressure, Lo (r = .592, p < .05), and TT (r = .514, p < .05); according to the right maximum pressure, PR (r = .539, p < .05), and Lo (r = .503, p < .05). In the left pressure distribution, the PR (r = -.521, p < .05) showed a negative correlation. In the Lt. group, the PT (r = -.591, p < .05) showed a negative correlation in the left pressure distribution. CONCLUSION: These results can be used as basic data for a body analysis study of elementary school baseball players in the future.

• The Journal of Churna Manual Medicine for Spine and Nerves
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• v.2 no.2
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• pp.1-16
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• 2007

Objectives : The purpose of this study was to identify spinal curvatures, plantar pressure and foot angles in a walking. Methods : 19 outpatients under 19 years old were included. Plantar pressure and foot angle in a walking were measured by using Gaitview AFA-50. Spinal curvatures were measured by using radiograph. Results : The cervical lordotic angle is significantly difference with left and right plantar pressure(p=0.027). The thoracic kyphotic angle is significantly difference with left and right plantar pressure(p=0.026). Cobb's angle is significantly difference with left and right plantar pressure(p=0.027). The other plantar pressure were no difference from spinal curvatures and foot angle in a walking. Conclusion : There were no correlation between plantar pressure, spinal curvatures and foot angle. We consider that needed more additional study.

• Transactions of the Korean Society of Automotive Engineers
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• v.6 no.5
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• pp.182-190
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• 1998

Behaviour of ultra-high pressure diesel spray in a constant-volume pressure chamber was studied with injection pressure ranging from 20 to 160㎫. Sprays were observed by the right angle scattering method. As a result, the spray tip penetration is first proportional to a time, and after that, it is proportional to 0.52 of the time during at the time of injection pressure and back pressure increase. An empirical correlation was made for the parameters of injection pressure, air-fuel density ratio, spray tip distance, spray angle, jet angle of spray and max. spray width.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.21 no.11
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• pp.1449-1457
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• 1997

Since a non-nulling method of five-hole probes is valid only when the flow angle is within the calibrated angle range, it can not be used in a complex flow field. Full angle range pressure coefficient maps show that widely used nulling methods do not guarantee correct alignment of the probe with the flow direction in the unknown complex flow field. Zone decision method and features of zone map were studied by investigating the full angle range pressure coefficient maps. A reliable and efficient new nulling algorithm using zone decision by pressure ordering is proposed and verified. Since the zone decision method by pressure ordering can decide whether the flow is within the calibration angle range or not, it is useful in wide angle nonnulling methods, too.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.17 no.3
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• pp.268-276
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• 2005

The aim of this paper is to suggest one efficient method for the various requirements of performance during the process designing and producing an impeller. The study considers that the revisions of a pitch angle of an impeller at an axial turbo fan affect an air flow rates and a static pressure rise. The axial turbo fan specified with the 250 Pa maximum static pressure and 1300 CMH fan air flow rates was tested and analyzed by CFD. The Numerical results show that the air flow rates are calculated to 1,175 CMH, 1,223 CMH, 1,270 CMH, 1,340 CMH and 800 CMH in cases that the pitch angles are $44^{\circ},\;49^{\circ},\;54^{\circ},\;59^{\circ},\;and\;64^{\circ}$ respectively. Also the static pressure rises are shown to 108 Pa, 122Pa, 141 Pa, 188 Pa and 63 Pa at the same cases. The air flow rate is increased linearly according to the changes of the pitch angle from $44^{\circ}\;to\;59^{\circ}$ and the maximum air flow rate passing the impeller is increased to $13\%$ over at the case of $59^{\circ}$ pitch angle compared with the reference case of $54^{\circ}$ pitch angle. The static pressure rise is increased linearly according to the changes of the pitch angle from $44^{\circ}\;to\;54^{\circ}$, too. The static pressure rise at the $59^{\circ}$ pitch angle is increased to $33\%$ over compared with the $54^{\circ}$ pitch angle. The result shows that the revisions of pitch angle make the static pressure rise increase widely. However the air flow rates and the static pressure rise at the $64^{\circ}$ pitch angle are suddenly decreased because of over-changed pitch angle.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2002.05a
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• pp.67-73
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• 2002

The characteristics of fuel spray influence on the engine performances such as power, fuel economy and emissions. therefore, the measurement of fuel spray characteristics is very important for the improvement of heat engine. The factor which controls the fuel spray is injection pressure, ambient pressure, engine speed et al.. In :his study, We measured spray angle, spray penetration and spray tip velocity considering injection pressure(10,14㎫), ambient pressure(3,4,5㎫), fuel pump speed(500,700,900rpm) in the high temperature and pressure chamber. Experimental results are summarized as follows: 1) Injection pressure influence on the characteristics of spray namely As Injection pressure Is increased, spray angle is decreased but spray penetration and spray tip velocity is increased. 2) Spray angle, spray penetration is increased by increasing the fuel pump speed. 3) Ambient pressure plays an important role in spray characteristics.